Updates
This commit is contained in:
26
fftw-3.3.10/doc/FAQ/Makefile.am
Normal file
26
fftw-3.3.10/doc/FAQ/Makefile.am
Normal file
@@ -0,0 +1,26 @@
|
||||
BFNNCONV_SRC = bfnnconv.pl m-ascii.pl m-html.pl m-info.pl m-lout.pl m-post.pl
|
||||
|
||||
FAQ = fftw-faq.ascii fftw-faq.html
|
||||
EXTRA_DIST = fftw-faq.bfnn $(FAQ) $(BFNNCONV_SRC) html.refs
|
||||
|
||||
html.refs2: html.refs
|
||||
cp -f ${srcdir}/html.refs html.refs2
|
||||
|
||||
fftw-faq.ascii: fftw-faq.html
|
||||
|
||||
# generates both fftw-faq.html and fftw-faq.ascii
|
||||
fftw-faq.html: $(BFNNCONV_SRC) fftw-faq.bfnn html.refs2
|
||||
@echo converting...
|
||||
perl -I${srcdir} ${srcdir}/bfnnconv.pl < ${srcdir}/fftw-faq.bfnn
|
||||
@echo converting again...
|
||||
perl -I${srcdir} ${srcdir}/bfnnconv.pl < ${srcdir}/fftw-faq.bfnn
|
||||
rm -f fftw-faq.ascii
|
||||
mv stdin.ascii fftw-faq.ascii
|
||||
rm -rf fftw-faq.html
|
||||
mv -f stdin.html fftw-faq.html
|
||||
|
||||
faq: $(FAQ)
|
||||
|
||||
clean-local:
|
||||
rm -f *~ core a.out *.lout *.ps *.info *.ascii *.xrefdb *.post
|
||||
rm -rf *.html html.refs2
|
||||
506
fftw-3.3.10/doc/FAQ/Makefile.in
Normal file
506
fftw-3.3.10/doc/FAQ/Makefile.in
Normal file
@@ -0,0 +1,506 @@
|
||||
# Makefile.in generated by automake 1.16.3 from Makefile.am.
|
||||
# @configure_input@
|
||||
|
||||
# Copyright (C) 1994-2020 Free Software Foundation, Inc.
|
||||
|
||||
# This Makefile.in is free software; the Free Software Foundation
|
||||
# gives unlimited permission to copy and/or distribute it,
|
||||
# with or without modifications, as long as this notice is preserved.
|
||||
|
||||
# This program is distributed in the hope that it will be useful,
|
||||
# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
|
||||
# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
|
||||
# PARTICULAR PURPOSE.
|
||||
|
||||
@SET_MAKE@
|
||||
VPATH = @srcdir@
|
||||
am__is_gnu_make = { \
|
||||
if test -z '$(MAKELEVEL)'; then \
|
||||
false; \
|
||||
elif test -n '$(MAKE_HOST)'; then \
|
||||
true; \
|
||||
elif test -n '$(MAKE_VERSION)' && test -n '$(CURDIR)'; then \
|
||||
true; \
|
||||
else \
|
||||
false; \
|
||||
fi; \
|
||||
}
|
||||
am__make_running_with_option = \
|
||||
case $${target_option-} in \
|
||||
?) ;; \
|
||||
*) echo "am__make_running_with_option: internal error: invalid" \
|
||||
"target option '$${target_option-}' specified" >&2; \
|
||||
exit 1;; \
|
||||
esac; \
|
||||
has_opt=no; \
|
||||
sane_makeflags=$$MAKEFLAGS; \
|
||||
if $(am__is_gnu_make); then \
|
||||
sane_makeflags=$$MFLAGS; \
|
||||
else \
|
||||
case $$MAKEFLAGS in \
|
||||
*\\[\ \ ]*) \
|
||||
bs=\\; \
|
||||
sane_makeflags=`printf '%s\n' "$$MAKEFLAGS" \
|
||||
| sed "s/$$bs$$bs[$$bs $$bs ]*//g"`;; \
|
||||
esac; \
|
||||
fi; \
|
||||
skip_next=no; \
|
||||
strip_trailopt () \
|
||||
{ \
|
||||
flg=`printf '%s\n' "$$flg" | sed "s/$$1.*$$//"`; \
|
||||
}; \
|
||||
for flg in $$sane_makeflags; do \
|
||||
test $$skip_next = yes && { skip_next=no; continue; }; \
|
||||
case $$flg in \
|
||||
*=*|--*) continue;; \
|
||||
-*I) strip_trailopt 'I'; skip_next=yes;; \
|
||||
-*I?*) strip_trailopt 'I';; \
|
||||
-*O) strip_trailopt 'O'; skip_next=yes;; \
|
||||
-*O?*) strip_trailopt 'O';; \
|
||||
-*l) strip_trailopt 'l'; skip_next=yes;; \
|
||||
-*l?*) strip_trailopt 'l';; \
|
||||
-[dEDm]) skip_next=yes;; \
|
||||
-[JT]) skip_next=yes;; \
|
||||
esac; \
|
||||
case $$flg in \
|
||||
*$$target_option*) has_opt=yes; break;; \
|
||||
esac; \
|
||||
done; \
|
||||
test $$has_opt = yes
|
||||
am__make_dryrun = (target_option=n; $(am__make_running_with_option))
|
||||
am__make_keepgoing = (target_option=k; $(am__make_running_with_option))
|
||||
pkgdatadir = $(datadir)/@PACKAGE@
|
||||
pkgincludedir = $(includedir)/@PACKAGE@
|
||||
pkglibdir = $(libdir)/@PACKAGE@
|
||||
pkglibexecdir = $(libexecdir)/@PACKAGE@
|
||||
am__cd = CDPATH="$${ZSH_VERSION+.}$(PATH_SEPARATOR)" && cd
|
||||
install_sh_DATA = $(install_sh) -c -m 644
|
||||
install_sh_PROGRAM = $(install_sh) -c
|
||||
install_sh_SCRIPT = $(install_sh) -c
|
||||
INSTALL_HEADER = $(INSTALL_DATA)
|
||||
transform = $(program_transform_name)
|
||||
NORMAL_INSTALL = :
|
||||
PRE_INSTALL = :
|
||||
POST_INSTALL = :
|
||||
NORMAL_UNINSTALL = :
|
||||
PRE_UNINSTALL = :
|
||||
POST_UNINSTALL = :
|
||||
build_triplet = @build@
|
||||
host_triplet = @host@
|
||||
subdir = doc/FAQ
|
||||
ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
|
||||
am__aclocal_m4_deps = $(top_srcdir)/m4/acx_mpi.m4 \
|
||||
$(top_srcdir)/m4/acx_pthread.m4 \
|
||||
$(top_srcdir)/m4/ax_cc_maxopt.m4 \
|
||||
$(top_srcdir)/m4/ax_check_compiler_flags.m4 \
|
||||
$(top_srcdir)/m4/ax_compiler_vendor.m4 \
|
||||
$(top_srcdir)/m4/ax_gcc_aligns_stack.m4 \
|
||||
$(top_srcdir)/m4/ax_gcc_version.m4 \
|
||||
$(top_srcdir)/m4/ax_openmp.m4 $(top_srcdir)/m4/libtool.m4 \
|
||||
$(top_srcdir)/m4/ltoptions.m4 $(top_srcdir)/m4/ltsugar.m4 \
|
||||
$(top_srcdir)/m4/ltversion.m4 $(top_srcdir)/m4/lt~obsolete.m4 \
|
||||
$(top_srcdir)/configure.ac
|
||||
am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
|
||||
$(ACLOCAL_M4)
|
||||
DIST_COMMON = $(srcdir)/Makefile.am $(am__DIST_COMMON)
|
||||
mkinstalldirs = $(install_sh) -d
|
||||
CONFIG_HEADER = $(top_builddir)/config.h
|
||||
CONFIG_CLEAN_FILES =
|
||||
CONFIG_CLEAN_VPATH_FILES =
|
||||
AM_V_P = $(am__v_P_@AM_V@)
|
||||
am__v_P_ = $(am__v_P_@AM_DEFAULT_V@)
|
||||
am__v_P_0 = false
|
||||
am__v_P_1 = :
|
||||
AM_V_GEN = $(am__v_GEN_@AM_V@)
|
||||
am__v_GEN_ = $(am__v_GEN_@AM_DEFAULT_V@)
|
||||
am__v_GEN_0 = @echo " GEN " $@;
|
||||
am__v_GEN_1 =
|
||||
AM_V_at = $(am__v_at_@AM_V@)
|
||||
am__v_at_ = $(am__v_at_@AM_DEFAULT_V@)
|
||||
am__v_at_0 = @
|
||||
am__v_at_1 =
|
||||
SOURCES =
|
||||
DIST_SOURCES =
|
||||
am__can_run_installinfo = \
|
||||
case $$AM_UPDATE_INFO_DIR in \
|
||||
n|no|NO) false;; \
|
||||
*) (install-info --version) >/dev/null 2>&1;; \
|
||||
esac
|
||||
am__tagged_files = $(HEADERS) $(SOURCES) $(TAGS_FILES) $(LISP)
|
||||
am__DIST_COMMON = $(srcdir)/Makefile.in
|
||||
DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
|
||||
ACLOCAL = @ACLOCAL@
|
||||
ALLOCA = @ALLOCA@
|
||||
ALTIVEC_CFLAGS = @ALTIVEC_CFLAGS@
|
||||
AMTAR = @AMTAR@
|
||||
AM_DEFAULT_VERBOSITY = @AM_DEFAULT_VERBOSITY@
|
||||
AR = @AR@
|
||||
AS = @AS@
|
||||
AUTOCONF = @AUTOCONF@
|
||||
AUTOHEADER = @AUTOHEADER@
|
||||
AUTOMAKE = @AUTOMAKE@
|
||||
AVX2_CFLAGS = @AVX2_CFLAGS@
|
||||
AVX512_CFLAGS = @AVX512_CFLAGS@
|
||||
AVX_128_FMA_CFLAGS = @AVX_128_FMA_CFLAGS@
|
||||
AVX_CFLAGS = @AVX_CFLAGS@
|
||||
AWK = @AWK@
|
||||
CC = @CC@
|
||||
CCDEPMODE = @CCDEPMODE@
|
||||
CFLAGS = @CFLAGS@
|
||||
CHECK_PL_OPTS = @CHECK_PL_OPTS@
|
||||
CPP = @CPP@
|
||||
CPPFLAGS = @CPPFLAGS@
|
||||
CYGPATH_W = @CYGPATH_W@
|
||||
C_FFTW_R2R_KIND = @C_FFTW_R2R_KIND@
|
||||
C_MPI_FINT = @C_MPI_FINT@
|
||||
DEFS = @DEFS@
|
||||
DEPDIR = @DEPDIR@
|
||||
DLLTOOL = @DLLTOOL@
|
||||
DSYMUTIL = @DSYMUTIL@
|
||||
DUMPBIN = @DUMPBIN@
|
||||
ECHO_C = @ECHO_C@
|
||||
ECHO_N = @ECHO_N@
|
||||
ECHO_T = @ECHO_T@
|
||||
EGREP = @EGREP@
|
||||
EXEEXT = @EXEEXT@
|
||||
F77 = @F77@
|
||||
FFLAGS = @FFLAGS@
|
||||
FGREP = @FGREP@
|
||||
FLIBS = @FLIBS@
|
||||
GREP = @GREP@
|
||||
INDENT = @INDENT@
|
||||
INSTALL = @INSTALL@
|
||||
INSTALL_DATA = @INSTALL_DATA@
|
||||
INSTALL_PROGRAM = @INSTALL_PROGRAM@
|
||||
INSTALL_SCRIPT = @INSTALL_SCRIPT@
|
||||
INSTALL_STRIP_PROGRAM = @INSTALL_STRIP_PROGRAM@
|
||||
KCVI_CFLAGS = @KCVI_CFLAGS@
|
||||
LD = @LD@
|
||||
LDFLAGS = @LDFLAGS@
|
||||
LIBOBJS = @LIBOBJS@
|
||||
LIBQUADMATH = @LIBQUADMATH@
|
||||
LIBS = @LIBS@
|
||||
LIBTOOL = @LIBTOOL@
|
||||
LIPO = @LIPO@
|
||||
LN_S = @LN_S@
|
||||
LTLIBOBJS = @LTLIBOBJS@
|
||||
LT_SYS_LIBRARY_PATH = @LT_SYS_LIBRARY_PATH@
|
||||
MAINT = @MAINT@
|
||||
MAKEINFO = @MAKEINFO@
|
||||
MANIFEST_TOOL = @MANIFEST_TOOL@
|
||||
MKDIR_P = @MKDIR_P@
|
||||
MPICC = @MPICC@
|
||||
MPILIBS = @MPILIBS@
|
||||
MPIRUN = @MPIRUN@
|
||||
NEON_CFLAGS = @NEON_CFLAGS@
|
||||
NM = @NM@
|
||||
NMEDIT = @NMEDIT@
|
||||
OBJDUMP = @OBJDUMP@
|
||||
OBJEXT = @OBJEXT@
|
||||
OCAMLBUILD = @OCAMLBUILD@
|
||||
OPENMP_CFLAGS = @OPENMP_CFLAGS@
|
||||
OTOOL = @OTOOL@
|
||||
OTOOL64 = @OTOOL64@
|
||||
PACKAGE = @PACKAGE@
|
||||
PACKAGE_BUGREPORT = @PACKAGE_BUGREPORT@
|
||||
PACKAGE_NAME = @PACKAGE_NAME@
|
||||
PACKAGE_STRING = @PACKAGE_STRING@
|
||||
PACKAGE_TARNAME = @PACKAGE_TARNAME@
|
||||
PACKAGE_URL = @PACKAGE_URL@
|
||||
PACKAGE_VERSION = @PACKAGE_VERSION@
|
||||
PATH_SEPARATOR = @PATH_SEPARATOR@
|
||||
POW_LIB = @POW_LIB@
|
||||
PRECISION = @PRECISION@
|
||||
PREC_SUFFIX = @PREC_SUFFIX@
|
||||
PTHREAD_CC = @PTHREAD_CC@
|
||||
PTHREAD_CFLAGS = @PTHREAD_CFLAGS@
|
||||
PTHREAD_LIBS = @PTHREAD_LIBS@
|
||||
RANLIB = @RANLIB@
|
||||
SED = @SED@
|
||||
SET_MAKE = @SET_MAKE@
|
||||
SHARED_VERSION_INFO = @SHARED_VERSION_INFO@
|
||||
SHELL = @SHELL@
|
||||
SSE2_CFLAGS = @SSE2_CFLAGS@
|
||||
STACK_ALIGN_CFLAGS = @STACK_ALIGN_CFLAGS@
|
||||
STRIP = @STRIP@
|
||||
THREADLIBS = @THREADLIBS@
|
||||
VERSION = @VERSION@
|
||||
VSX_CFLAGS = @VSX_CFLAGS@
|
||||
abs_builddir = @abs_builddir@
|
||||
abs_srcdir = @abs_srcdir@
|
||||
abs_top_builddir = @abs_top_builddir@
|
||||
abs_top_srcdir = @abs_top_srcdir@
|
||||
ac_ct_AR = @ac_ct_AR@
|
||||
ac_ct_CC = @ac_ct_CC@
|
||||
ac_ct_DUMPBIN = @ac_ct_DUMPBIN@
|
||||
ac_ct_F77 = @ac_ct_F77@
|
||||
acx_pthread_config = @acx_pthread_config@
|
||||
am__include = @am__include@
|
||||
am__leading_dot = @am__leading_dot@
|
||||
am__quote = @am__quote@
|
||||
am__tar = @am__tar@
|
||||
am__untar = @am__untar@
|
||||
bindir = @bindir@
|
||||
build = @build@
|
||||
build_alias = @build_alias@
|
||||
build_cpu = @build_cpu@
|
||||
build_os = @build_os@
|
||||
build_vendor = @build_vendor@
|
||||
builddir = @builddir@
|
||||
datadir = @datadir@
|
||||
datarootdir = @datarootdir@
|
||||
docdir = @docdir@
|
||||
dvidir = @dvidir@
|
||||
exec_prefix = @exec_prefix@
|
||||
host = @host@
|
||||
host_alias = @host_alias@
|
||||
host_cpu = @host_cpu@
|
||||
host_os = @host_os@
|
||||
host_vendor = @host_vendor@
|
||||
htmldir = @htmldir@
|
||||
includedir = @includedir@
|
||||
infodir = @infodir@
|
||||
install_sh = @install_sh@
|
||||
libdir = @libdir@
|
||||
libexecdir = @libexecdir@
|
||||
localedir = @localedir@
|
||||
localstatedir = @localstatedir@
|
||||
mandir = @mandir@
|
||||
mkdir_p = @mkdir_p@
|
||||
oldincludedir = @oldincludedir@
|
||||
pdfdir = @pdfdir@
|
||||
prefix = @prefix@
|
||||
program_transform_name = @program_transform_name@
|
||||
psdir = @psdir@
|
||||
runstatedir = @runstatedir@
|
||||
sbindir = @sbindir@
|
||||
sharedstatedir = @sharedstatedir@
|
||||
srcdir = @srcdir@
|
||||
sysconfdir = @sysconfdir@
|
||||
target_alias = @target_alias@
|
||||
top_build_prefix = @top_build_prefix@
|
||||
top_builddir = @top_builddir@
|
||||
top_srcdir = @top_srcdir@
|
||||
BFNNCONV_SRC = bfnnconv.pl m-ascii.pl m-html.pl m-info.pl m-lout.pl m-post.pl
|
||||
FAQ = fftw-faq.ascii fftw-faq.html
|
||||
EXTRA_DIST = fftw-faq.bfnn $(FAQ) $(BFNNCONV_SRC) html.refs
|
||||
all: all-am
|
||||
|
||||
.SUFFIXES:
|
||||
$(srcdir)/Makefile.in: @MAINTAINER_MODE_TRUE@ $(srcdir)/Makefile.am $(am__configure_deps)
|
||||
@for dep in $?; do \
|
||||
case '$(am__configure_deps)' in \
|
||||
*$$dep*) \
|
||||
( cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh ) \
|
||||
&& { if test -f $@; then exit 0; else break; fi; }; \
|
||||
exit 1;; \
|
||||
esac; \
|
||||
done; \
|
||||
echo ' cd $(top_srcdir) && $(AUTOMAKE) --gnu doc/FAQ/Makefile'; \
|
||||
$(am__cd) $(top_srcdir) && \
|
||||
$(AUTOMAKE) --gnu doc/FAQ/Makefile
|
||||
Makefile: $(srcdir)/Makefile.in $(top_builddir)/config.status
|
||||
@case '$?' in \
|
||||
*config.status*) \
|
||||
cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh;; \
|
||||
*) \
|
||||
echo ' cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__maybe_remake_depfiles)'; \
|
||||
cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__maybe_remake_depfiles);; \
|
||||
esac;
|
||||
|
||||
$(top_builddir)/config.status: $(top_srcdir)/configure $(CONFIG_STATUS_DEPENDENCIES)
|
||||
cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
|
||||
|
||||
$(top_srcdir)/configure: @MAINTAINER_MODE_TRUE@ $(am__configure_deps)
|
||||
cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
|
||||
$(ACLOCAL_M4): @MAINTAINER_MODE_TRUE@ $(am__aclocal_m4_deps)
|
||||
cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
|
||||
$(am__aclocal_m4_deps):
|
||||
|
||||
mostlyclean-libtool:
|
||||
-rm -f *.lo
|
||||
|
||||
clean-libtool:
|
||||
-rm -rf .libs _libs
|
||||
tags TAGS:
|
||||
|
||||
ctags CTAGS:
|
||||
|
||||
cscope cscopelist:
|
||||
|
||||
|
||||
distdir: $(BUILT_SOURCES)
|
||||
$(MAKE) $(AM_MAKEFLAGS) distdir-am
|
||||
|
||||
distdir-am: $(DISTFILES)
|
||||
@srcdirstrip=`echo "$(srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
|
||||
topsrcdirstrip=`echo "$(top_srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
|
||||
list='$(DISTFILES)'; \
|
||||
dist_files=`for file in $$list; do echo $$file; done | \
|
||||
sed -e "s|^$$srcdirstrip/||;t" \
|
||||
-e "s|^$$topsrcdirstrip/|$(top_builddir)/|;t"`; \
|
||||
case $$dist_files in \
|
||||
*/*) $(MKDIR_P) `echo "$$dist_files" | \
|
||||
sed '/\//!d;s|^|$(distdir)/|;s,/[^/]*$$,,' | \
|
||||
sort -u` ;; \
|
||||
esac; \
|
||||
for file in $$dist_files; do \
|
||||
if test -f $$file || test -d $$file; then d=.; else d=$(srcdir); fi; \
|
||||
if test -d $$d/$$file; then \
|
||||
dir=`echo "/$$file" | sed -e 's,/[^/]*$$,,'`; \
|
||||
if test -d "$(distdir)/$$file"; then \
|
||||
find "$(distdir)/$$file" -type d ! -perm -700 -exec chmod u+rwx {} \;; \
|
||||
fi; \
|
||||
if test -d $(srcdir)/$$file && test $$d != $(srcdir); then \
|
||||
cp -fpR $(srcdir)/$$file "$(distdir)$$dir" || exit 1; \
|
||||
find "$(distdir)/$$file" -type d ! -perm -700 -exec chmod u+rwx {} \;; \
|
||||
fi; \
|
||||
cp -fpR $$d/$$file "$(distdir)$$dir" || exit 1; \
|
||||
else \
|
||||
test -f "$(distdir)/$$file" \
|
||||
|| cp -p $$d/$$file "$(distdir)/$$file" \
|
||||
|| exit 1; \
|
||||
fi; \
|
||||
done
|
||||
check-am: all-am
|
||||
check: check-am
|
||||
all-am: Makefile
|
||||
installdirs:
|
||||
install: install-am
|
||||
install-exec: install-exec-am
|
||||
install-data: install-data-am
|
||||
uninstall: uninstall-am
|
||||
|
||||
install-am: all-am
|
||||
@$(MAKE) $(AM_MAKEFLAGS) install-exec-am install-data-am
|
||||
|
||||
installcheck: installcheck-am
|
||||
install-strip:
|
||||
if test -z '$(STRIP)'; then \
|
||||
$(MAKE) $(AM_MAKEFLAGS) INSTALL_PROGRAM="$(INSTALL_STRIP_PROGRAM)" \
|
||||
install_sh_PROGRAM="$(INSTALL_STRIP_PROGRAM)" INSTALL_STRIP_FLAG=-s \
|
||||
install; \
|
||||
else \
|
||||
$(MAKE) $(AM_MAKEFLAGS) INSTALL_PROGRAM="$(INSTALL_STRIP_PROGRAM)" \
|
||||
install_sh_PROGRAM="$(INSTALL_STRIP_PROGRAM)" INSTALL_STRIP_FLAG=-s \
|
||||
"INSTALL_PROGRAM_ENV=STRIPPROG='$(STRIP)'" install; \
|
||||
fi
|
||||
mostlyclean-generic:
|
||||
|
||||
clean-generic:
|
||||
|
||||
distclean-generic:
|
||||
-test -z "$(CONFIG_CLEAN_FILES)" || rm -f $(CONFIG_CLEAN_FILES)
|
||||
-test . = "$(srcdir)" || test -z "$(CONFIG_CLEAN_VPATH_FILES)" || rm -f $(CONFIG_CLEAN_VPATH_FILES)
|
||||
|
||||
maintainer-clean-generic:
|
||||
@echo "This command is intended for maintainers to use"
|
||||
@echo "it deletes files that may require special tools to rebuild."
|
||||
clean: clean-am
|
||||
|
||||
clean-am: clean-generic clean-libtool clean-local mostlyclean-am
|
||||
|
||||
distclean: distclean-am
|
||||
-rm -f Makefile
|
||||
distclean-am: clean-am distclean-generic
|
||||
|
||||
dvi: dvi-am
|
||||
|
||||
dvi-am:
|
||||
|
||||
html: html-am
|
||||
|
||||
html-am:
|
||||
|
||||
info: info-am
|
||||
|
||||
info-am:
|
||||
|
||||
install-data-am:
|
||||
|
||||
install-dvi: install-dvi-am
|
||||
|
||||
install-dvi-am:
|
||||
|
||||
install-exec-am:
|
||||
|
||||
install-html: install-html-am
|
||||
|
||||
install-html-am:
|
||||
|
||||
install-info: install-info-am
|
||||
|
||||
install-info-am:
|
||||
|
||||
install-man:
|
||||
|
||||
install-pdf: install-pdf-am
|
||||
|
||||
install-pdf-am:
|
||||
|
||||
install-ps: install-ps-am
|
||||
|
||||
install-ps-am:
|
||||
|
||||
installcheck-am:
|
||||
|
||||
maintainer-clean: maintainer-clean-am
|
||||
-rm -f Makefile
|
||||
maintainer-clean-am: distclean-am maintainer-clean-generic
|
||||
|
||||
mostlyclean: mostlyclean-am
|
||||
|
||||
mostlyclean-am: mostlyclean-generic mostlyclean-libtool
|
||||
|
||||
pdf: pdf-am
|
||||
|
||||
pdf-am:
|
||||
|
||||
ps: ps-am
|
||||
|
||||
ps-am:
|
||||
|
||||
uninstall-am:
|
||||
|
||||
.MAKE: install-am install-strip
|
||||
|
||||
.PHONY: all all-am check check-am clean clean-generic clean-libtool \
|
||||
clean-local cscopelist-am ctags-am distclean distclean-generic \
|
||||
distclean-libtool distdir dvi dvi-am html html-am info info-am \
|
||||
install install-am install-data install-data-am install-dvi \
|
||||
install-dvi-am install-exec install-exec-am install-html \
|
||||
install-html-am install-info install-info-am install-man \
|
||||
install-pdf install-pdf-am install-ps install-ps-am \
|
||||
install-strip installcheck installcheck-am installdirs \
|
||||
maintainer-clean maintainer-clean-generic mostlyclean \
|
||||
mostlyclean-generic mostlyclean-libtool pdf pdf-am ps ps-am \
|
||||
tags-am uninstall uninstall-am
|
||||
|
||||
.PRECIOUS: Makefile
|
||||
|
||||
|
||||
html.refs2: html.refs
|
||||
cp -f ${srcdir}/html.refs html.refs2
|
||||
|
||||
fftw-faq.ascii: fftw-faq.html
|
||||
|
||||
# generates both fftw-faq.html and fftw-faq.ascii
|
||||
fftw-faq.html: $(BFNNCONV_SRC) fftw-faq.bfnn html.refs2
|
||||
@echo converting...
|
||||
perl -I${srcdir} ${srcdir}/bfnnconv.pl < ${srcdir}/fftw-faq.bfnn
|
||||
@echo converting again...
|
||||
perl -I${srcdir} ${srcdir}/bfnnconv.pl < ${srcdir}/fftw-faq.bfnn
|
||||
rm -f fftw-faq.ascii
|
||||
mv stdin.ascii fftw-faq.ascii
|
||||
rm -rf fftw-faq.html
|
||||
mv -f stdin.html fftw-faq.html
|
||||
|
||||
faq: $(FAQ)
|
||||
|
||||
clean-local:
|
||||
rm -f *~ core a.out *.lout *.ps *.info *.ascii *.xrefdb *.post
|
||||
rm -rf *.html html.refs2
|
||||
|
||||
# Tell versions [3.59,3.63) of GNU make to not export all variables.
|
||||
# Otherwise a system limit (for SysV at least) may be exceeded.
|
||||
.NOEXPORT:
|
||||
298
fftw-3.3.10/doc/FAQ/bfnnconv.pl
Executable file
298
fftw-3.3.10/doc/FAQ/bfnnconv.pl
Executable file
@@ -0,0 +1,298 @@
|
||||
#!/usr/bin/perl --
|
||||
# Copyright (C) 1993-1995 Ian Jackson.
|
||||
|
||||
# This file is free software; you can redistribute it and/or modify
|
||||
# it under the terms of the GNU General Public License as published by
|
||||
# the Free Software Foundation; either version 2, or (at your option)
|
||||
# any later version.
|
||||
|
||||
# It is distributed in the hope that it will be useful,
|
||||
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
# GNU General Public License for more details.
|
||||
|
||||
# You should have received a copy of the GNU General Public License
|
||||
# along with GNU Emacs; see the file COPYING. If not, write to
|
||||
# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||||
# Boston, MA 02111-1307, USA.
|
||||
|
||||
# (Note: I do not consider works produced using these BFNN processing
|
||||
# tools to be derivative works of the tools, so they are NOT covered
|
||||
# by the GPL. However, I would appreciate it if you credited me if
|
||||
# appropriate in any documents you format using BFNN.)
|
||||
|
||||
@outputs=('ascii','info','html');
|
||||
|
||||
while ($ARGV[0] =~ m/^\-/) {
|
||||
$_= shift(@ARGV);
|
||||
if (m/^-only/) {
|
||||
@outputs= (shift(@ARGV));
|
||||
} else {
|
||||
warn "unknown option `$_' ignored";
|
||||
}
|
||||
}
|
||||
|
||||
$prefix= $ARGV[0];
|
||||
$prefix= 'stdin' unless length($prefix);
|
||||
$prefix =~ s/\.bfnn$//;
|
||||
|
||||
if (open(O,"$prefix.xrefdb")) {
|
||||
@xrefdb= <O>;
|
||||
close(O);
|
||||
} else {
|
||||
warn "no $prefix.xrefdb ($!)";
|
||||
}
|
||||
|
||||
$section= -1;
|
||||
for $thisxr (@xrefdb) {
|
||||
$_= $thisxr;
|
||||
chop;
|
||||
if (m/^Q (\w+) ((\d+)\.(\d+)) (.*)$/) {
|
||||
$qrefn{$1}= $2;
|
||||
$qreft{$1}= $5;
|
||||
$qn2ref{$3,$4}= $1;
|
||||
$maxsection= $3;
|
||||
$maxquestion[$3]= $4;
|
||||
} elsif (m/^S (\d+) /) {
|
||||
$maxsection= $1;
|
||||
$sn2title{$1}=$';
|
||||
}
|
||||
}
|
||||
|
||||
open(U,">$prefix.xrefdb-new");
|
||||
|
||||
for $x (@outputs) { require("m-$x.pl"); }
|
||||
|
||||
&call('init');
|
||||
|
||||
while (<>) {
|
||||
chop;
|
||||
next if m/^\\comment\b/;
|
||||
if (!m/\S/) {
|
||||
&call('endpara');
|
||||
next;
|
||||
}
|
||||
if (s/^\\section +//) {
|
||||
$line= $_;
|
||||
$section++; $question=0;
|
||||
print U "S $section $line\n";
|
||||
$|=1; print "S$section",' 'x10,"\r"; $|=0;
|
||||
&call('endpara');
|
||||
&call('startmajorheading',"$section",
|
||||
"Section $section",
|
||||
$section<$maxsection ? "Section ".($section+1) : '',
|
||||
$section>1 ? 'Section '.($section-1) : 'Top');
|
||||
&text($line);
|
||||
&call('endmajorheading');
|
||||
if ($section) {
|
||||
&call('endpara');
|
||||
&call('startindex');
|
||||
for $thisxr (@xrefdb) {
|
||||
$_= $thisxr;
|
||||
chop;
|
||||
if (m/^Q (\w+) (\d+)\.(\d+) (.*)$/) {
|
||||
$ref= $1; $num1= $2; $num2= $3; $text= $4;
|
||||
next unless $num1 == $section;
|
||||
&call('startindexitem',$ref,"Q$num1.$num2","Question $num1.$num2");
|
||||
&text($text);
|
||||
&call('endindexitem');
|
||||
}
|
||||
}
|
||||
&call('endindex');
|
||||
}
|
||||
} elsif (s/^\\question \d{2}[a-z]{3}((:\w+)?) +//) {
|
||||
$line= $_;
|
||||
$question++;
|
||||
$qrefstring= $1;
|
||||
$qrefstring= "q_${section}_$question" unless $qrefstring =~ s/^://;
|
||||
print U "Q $qrefstring $section.$question $line\n";
|
||||
$|=1; print "Q$section.$question",' 'x10,"\r"; $|=0;
|
||||
&call('endpara');
|
||||
&call('startminorheading',$qrefstring,
|
||||
"Question $section.$question",
|
||||
$question < $maxquestion[$section] ? "Question $section.".($question+1) :
|
||||
$section < $maxsection ? "Question ".($section+1).".1" : '',
|
||||
$question > 1 ? "Question $section.".($question-1) :
|
||||
$section > 1 ? "Question ".($section-1).'.'.($maxquestion[$section-1]) :
|
||||
'Top',
|
||||
"Section $section");
|
||||
&text("Question $section.$question. $line");
|
||||
&call('endminorheading');
|
||||
} elsif (s/^\\only +//) {
|
||||
@saveoutputs= @outputs;
|
||||
@outputs=();
|
||||
for $x (split(/\s+/,$_)) {
|
||||
push(@outputs,$x) if grep($x eq $_, @saveoutputs);
|
||||
}
|
||||
} elsif (s/^\\endonly$//) {
|
||||
@outputs= @saveoutputs;
|
||||
} elsif (s/^\\copyto +//) {
|
||||
$fh= $';
|
||||
while(<>) {
|
||||
last if m/^\\endcopy$/;
|
||||
while (s/^([^\`]*)\`//) {
|
||||
print $fh $1;
|
||||
m/([^\\])\`/ || warn "`$_'";
|
||||
$_= $';
|
||||
$cmd= $`.$1;
|
||||
$it= `$cmd`; chop $it;
|
||||
print $fh $it;
|
||||
}
|
||||
print $fh $_;
|
||||
}
|
||||
} elsif (m/\\index$/) {
|
||||
&call('startindex');
|
||||
for $thisxr (@xrefdb) {
|
||||
$_= $thisxr;
|
||||
chop;
|
||||
if (m/^Q (\w+) (\d+\.\d+) (.*)$/) {
|
||||
$ref= $1; $num= $2; $text= $3;
|
||||
&call('startindexitem',$ref,"Q$num","Question $num");
|
||||
&text($text);
|
||||
&call('endindexitem');
|
||||
} elsif (m/^S (\d+) (.*)$/) {
|
||||
$num= $1; $text= $2;
|
||||
next unless $num;
|
||||
&call('startindexmainitem',"s_$num",
|
||||
"Section $num.","Section $num");
|
||||
&text($text);
|
||||
&call('endindexitem');
|
||||
} else {
|
||||
warn $_;
|
||||
}
|
||||
}
|
||||
&call('endindex');
|
||||
} elsif (m/^\\call-(\w+) +(\w+)\s*(.*)$/) {
|
||||
$fn= $1.'_'.$2;
|
||||
eval { &$fn($3); };
|
||||
warn $@ if length($@);
|
||||
} elsif (m/^\\call +(\w+)\s*(.*)$/) {
|
||||
eval { &call($1,$2); };
|
||||
warn $@ if length($@);
|
||||
} elsif (s/^\\set +(\w+)\s*//) {
|
||||
$svalue= $'; $svari= $1;
|
||||
eval("\$user_$svari=\$svalue"); $@ && warn "setting $svalue failed: $@\n";
|
||||
} elsif (m/^\\verbatim$/) {
|
||||
&call('startverbatim');
|
||||
while (<>) {
|
||||
chop;
|
||||
last if m/^\\endverbatim$/;
|
||||
&call('verbatim',$_);
|
||||
}
|
||||
&call('endverbatim');
|
||||
} else {
|
||||
s/\.$/\. /;
|
||||
&text($_." ");
|
||||
}
|
||||
}
|
||||
|
||||
print ' 'x25,"\r";
|
||||
&call('finish');
|
||||
rename("$prefix.xrefdb-new","$prefix.xrefdb") || warn "rename xrefdb: $!";
|
||||
exit 0;
|
||||
|
||||
|
||||
sub text {
|
||||
local($in,$rhs,$word,$refn,$reft,$fn,$style);
|
||||
$in= "$holdover$_[0]";
|
||||
$holdover= '';
|
||||
while ($in =~ m/\\/) {
|
||||
#print STDERR ">$`##$'\n";
|
||||
$rhs=$';
|
||||
&call('text',$`);
|
||||
$_= $rhs;
|
||||
if (m/^\w+ $/) {
|
||||
$holdover= "\\$&";
|
||||
$in= '';
|
||||
} elsif (s/^fn\s+([^\s\\]*\w)//) {
|
||||
$in= $_;
|
||||
$word= $1;
|
||||
&call('courier');
|
||||
&call('text',$word);
|
||||
&call('endcourier');
|
||||
} elsif (s/^tab\s+(\d+)\s+//) {
|
||||
$in= $_; &call('tab',$1);
|
||||
} elsif (s/^nl\s+//) {
|
||||
$in= $_; &call('newline');
|
||||
} elsif (s/^qref\s+(\w+)//) {
|
||||
$refn= $qrefn{$1};
|
||||
$reft= $qreft{$1};
|
||||
if (!length($refn)) {
|
||||
warn "unknown question `$1'";
|
||||
}
|
||||
$in= "$`\\pageref:$1:$refn:$reft\\endpageref.$_";
|
||||
} elsif (s/^pageref:(\w+):([^:\n]+)://) {
|
||||
$in= $_;
|
||||
&call('pageref',$1,$2);
|
||||
} elsif (s/^endpageref\.//) {
|
||||
$in= $_; &call('endpageref');
|
||||
} elsif (s/^(\w+)\{//) {
|
||||
$in= $_; $fn= $1;
|
||||
eval { &call("$fn"); };
|
||||
if (length($@)) { warn $@; $fn= 'x'; }
|
||||
push(@styles,$fn);
|
||||
} elsif (s/^\}//) {
|
||||
$in= $_;
|
||||
$fn= pop(@styles);
|
||||
if ($fn ne 'x') { &call("end$fn"); }
|
||||
} elsif (s/^\\//) {
|
||||
$in= $_;
|
||||
&call('text',"\\");
|
||||
} elsif (s,^(\w+)\s+([-A-Za-z0-9.\@:/]*\w),,) {
|
||||
#print STDERR "**$&**$_\n";
|
||||
$in= $_;
|
||||
$style=$1; $word= $2;
|
||||
&call($style);
|
||||
&call('text',$word);
|
||||
&call("end$style");
|
||||
} else {
|
||||
warn "unknown control `\\$_'";
|
||||
$in= $_;
|
||||
}
|
||||
}
|
||||
&call('text',$in);
|
||||
}
|
||||
|
||||
|
||||
sub call {
|
||||
local ($fnbase, @callargs) = @_;
|
||||
local ($coutput);
|
||||
for $coutput (@outputs) {
|
||||
if ($fnbase eq 'text' && eval("\@${coutput}_cmds")) {
|
||||
#print STDERR "special handling text (@callargs) for $coutput\n";
|
||||
$evstrg= "\$${coutput}_args[\$#${coutput}_args].=\"\@callargs\"";
|
||||
eval($evstrg);
|
||||
length($@) && warn "call adding for $coutput (($evstrg)): $@";
|
||||
} else {
|
||||
$fntc= $coutput.'_'.$fnbase;
|
||||
&$fntc(@callargs);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
sub recurse {
|
||||
local (@outputs) = $coutput;
|
||||
local ($holdover);
|
||||
&text($_[0]);
|
||||
}
|
||||
|
||||
|
||||
sub arg {
|
||||
#print STDERR "arg($_[0]) from $coutput\n";
|
||||
$cmd= $_[0];
|
||||
eval("push(\@${coutput}_cmds,\$cmd); push(\@${coutput}_args,'')");
|
||||
length($@) && warn "arg setting up for $coutput: $@";
|
||||
}
|
||||
|
||||
sub endarg {
|
||||
#print STDERR "endarg($_[0]) from $coutput\n";
|
||||
$evstrg= "\$${coutput}_cmd= \$cmd= pop(\@${coutput}_cmds); ".
|
||||
"\$${coutput}_arg= \$arg= pop(\@${coutput}_args); ";
|
||||
eval($evstrg);
|
||||
length($@) && warn "endarg extracting for $coutput (($evstrg)): $@";
|
||||
#print STDERR ">call $coutput $cmd $arg< (($evstrg))\n";
|
||||
$evstrg= "&${coutput}_do_${cmd}(\$arg)";
|
||||
eval($evstrg);
|
||||
length($@) && warn "endarg running ${coutput}_do_${cmd} (($evstrg)): $@";
|
||||
}
|
||||
842
fftw-3.3.10/doc/FAQ/fftw-faq.ascii
Normal file
842
fftw-3.3.10/doc/FAQ/fftw-faq.ascii
Normal file
@@ -0,0 +1,842 @@
|
||||
FFTW FREQUENTLY ASKED QUESTIONS WITH ANSWERS
|
||||
14 Sep 2021
|
||||
Matteo Frigo
|
||||
Steven G. Johnson
|
||||
<fftw@fftw.org>
|
||||
|
||||
This is the list of Frequently Asked Questions about FFTW, a collection of
|
||||
fast C routines for computing the Discrete Fourier Transform in one or
|
||||
more dimensions.
|
||||
|
||||
===============================================================================
|
||||
|
||||
Index
|
||||
|
||||
Section 1. Introduction and General Information
|
||||
Q1.1 What is FFTW?
|
||||
Q1.2 How do I obtain FFTW?
|
||||
Q1.3 Is FFTW free software?
|
||||
Q1.4 What is this about non-free licenses?
|
||||
Q1.5 In the West? I thought MIT was in the East?
|
||||
|
||||
Section 2. Installing FFTW
|
||||
Q2.1 Which systems does FFTW run on?
|
||||
Q2.2 Does FFTW run on Windows?
|
||||
Q2.3 My compiler has trouble with FFTW.
|
||||
Q2.4 FFTW does not compile on Solaris, complaining about const.
|
||||
Q2.5 What's the difference between --enable-3dnow and --enable-k7?
|
||||
Q2.6 What's the difference between the fma and the non-fma versions?
|
||||
Q2.7 Which language is FFTW written in?
|
||||
Q2.8 Can I call FFTW from Fortran?
|
||||
Q2.9 Can I call FFTW from C++?
|
||||
Q2.10 Why isn't FFTW written in Fortran/C++?
|
||||
Q2.11 How do I compile FFTW to run in single precision?
|
||||
Q2.12 --enable-k7 does not work on x86-64
|
||||
|
||||
Section 3. Using FFTW
|
||||
Q3.1 Why not support the FFTW 2 interface in FFTW 3?
|
||||
Q3.2 Why do FFTW 3 plans encapsulate the input/output arrays and not ju
|
||||
Q3.3 FFTW seems really slow.
|
||||
Q3.4 FFTW slows down after repeated calls.
|
||||
Q3.5 An FFTW routine is crashing when I call it.
|
||||
Q3.6 My Fortran program crashes when calling FFTW.
|
||||
Q3.7 FFTW gives results different from my old FFT.
|
||||
Q3.8 FFTW gives different results between runs
|
||||
Q3.9 Can I save FFTW's plans?
|
||||
Q3.10 Why does your inverse transform return a scaled result?
|
||||
Q3.11 How can I make FFTW put the origin (zero frequency) at the center
|
||||
Q3.12 How do I FFT an image/audio file in *foobar* format?
|
||||
Q3.13 My program does not link (on Unix).
|
||||
Q3.14 I included your header, but linking still fails.
|
||||
Q3.15 My program crashes, complaining about stack space.
|
||||
Q3.16 FFTW seems to have a memory leak.
|
||||
Q3.17 The output of FFTW's transform is all zeros.
|
||||
Q3.18 How do I call FFTW from the Microsoft language du jour?
|
||||
Q3.19 Can I compute only a subset of the DFT outputs?
|
||||
Q3.20 Can I use FFTW's routines for in-place and out-of-place matrix tra
|
||||
|
||||
Section 4. Internals of FFTW
|
||||
Q4.1 How does FFTW work?
|
||||
Q4.2 Why is FFTW so fast?
|
||||
|
||||
Section 5. Known bugs
|
||||
Q5.1 FFTW 1.1 crashes in rfftwnd on Linux.
|
||||
Q5.2 The MPI transforms in FFTW 1.2 give incorrect results/leak memory.
|
||||
Q5.3 The test programs in FFTW 1.2.1 fail when I change FFTW to use sin
|
||||
Q5.4 The test program in FFTW 1.2.1 fails for n > 46340.
|
||||
Q5.5 The threaded code fails on Linux Redhat 5.0
|
||||
Q5.6 FFTW 2.0's rfftwnd fails for rank > 1 transforms with a final dime
|
||||
Q5.7 FFTW 2.0's complex transforms give the wrong results with prime fa
|
||||
Q5.8 FFTW 2.1.1's MPI test programs crash with MPICH.
|
||||
Q5.9 FFTW 2.1.2's multi-threaded transforms don't work on AIX.
|
||||
Q5.10 FFTW 2.1.2's complex transforms give incorrect results for large p
|
||||
Q5.11 FFTW 2.1.3's multi-threaded transforms don't give any speedup on S
|
||||
Q5.12 FFTW 2.1.3 crashes on AIX.
|
||||
|
||||
===============================================================================
|
||||
|
||||
Section 1. Introduction and General Information
|
||||
|
||||
Q1.1 What is FFTW?
|
||||
Q1.2 How do I obtain FFTW?
|
||||
Q1.3 Is FFTW free software?
|
||||
Q1.4 What is this about non-free licenses?
|
||||
Q1.5 In the West? I thought MIT was in the East?
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 1.1. What is FFTW?
|
||||
|
||||
FFTW is a free collection of fast C routines for computing the Discrete
|
||||
Fourier Transform in one or more dimensions. It includes complex, real,
|
||||
symmetric, and parallel transforms, and can handle arbitrary array sizes
|
||||
efficiently. FFTW is typically faster than other publically-available FFT
|
||||
implementations, and is even competitive with vendor-tuned libraries.
|
||||
(See our web page for extensive benchmarks.) To achieve this performance,
|
||||
FFTW uses novel code-generation and runtime self-optimization techniques
|
||||
(along with many other tricks).
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 1.2. How do I obtain FFTW?
|
||||
|
||||
FFTW can be found at the FFTW web page. You can also retrieve it from
|
||||
ftp.fftw.org in /pub/fftw.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 1.3. Is FFTW free software?
|
||||
|
||||
Starting with version 1.3, FFTW is Free Software in the technical sense
|
||||
defined by the Free Software Foundation (see Categories of Free and
|
||||
Non-Free Software), and is distributed under the terms of the GNU General
|
||||
Public License. Previous versions of FFTW were distributed without fee
|
||||
for noncommercial use, but were not technically ``free.''
|
||||
|
||||
Non-free licenses for FFTW are also available that permit different terms
|
||||
of use than the GPL.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 1.4. What is this about non-free licenses?
|
||||
|
||||
The non-free licenses are for companies that wish to use FFTW in their
|
||||
products but are unwilling to release their software under the GPL (which
|
||||
would require them to release source code and allow free redistribution).
|
||||
Such users can purchase an unlimited-use license from MIT. Contact us for
|
||||
more details.
|
||||
|
||||
We could instead have released FFTW under the LGPL, or even disallowed
|
||||
non-Free usage. Suffice it to say, however, that MIT owns the copyright
|
||||
to FFTW and they only let us GPL it because we convinced them that it
|
||||
would neither affect their licensing revenue nor irritate existing
|
||||
licensees.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 1.5. In the West? I thought MIT was in the East?
|
||||
|
||||
Not to an Italian. You could say that we're a Spaghetti Western (with
|
||||
apologies to Sergio Leone).
|
||||
|
||||
===============================================================================
|
||||
|
||||
Section 2. Installing FFTW
|
||||
|
||||
Q2.1 Which systems does FFTW run on?
|
||||
Q2.2 Does FFTW run on Windows?
|
||||
Q2.3 My compiler has trouble with FFTW.
|
||||
Q2.4 FFTW does not compile on Solaris, complaining about const.
|
||||
Q2.5 What's the difference between --enable-3dnow and --enable-k7?
|
||||
Q2.6 What's the difference between the fma and the non-fma versions?
|
||||
Q2.7 Which language is FFTW written in?
|
||||
Q2.8 Can I call FFTW from Fortran?
|
||||
Q2.9 Can I call FFTW from C++?
|
||||
Q2.10 Why isn't FFTW written in Fortran/C++?
|
||||
Q2.11 How do I compile FFTW to run in single precision?
|
||||
Q2.12 --enable-k7 does not work on x86-64
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.1. Which systems does FFTW run on?
|
||||
|
||||
FFTW is written in ANSI C, and should work on any system with a decent C
|
||||
compiler. (See also Q2.2 `Does FFTW run on Windows?', Q2.3 `My compiler
|
||||
has trouble with FFTW.'.) FFTW can also take advantage of certain
|
||||
hardware-specific features, such as cycle counters and SIMD instructions,
|
||||
but this is optional.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.2. Does FFTW run on Windows?
|
||||
|
||||
Yes, many people have reported successfully using FFTW on Windows with
|
||||
various compilers. FFTW was not developed on Windows, but the source code
|
||||
is essentially straight ANSI C. See also the FFTW Windows installation
|
||||
notes, Q2.3 `My compiler has trouble with FFTW.', and Q3.18 `How do I call
|
||||
FFTW from the Microsoft language du jour?'.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.3. My compiler has trouble with FFTW.
|
||||
|
||||
Complain fiercely to the vendor of the compiler.
|
||||
|
||||
We have successfully used gcc 3.2.x on x86 and PPC, a recent Compaq C
|
||||
compiler for Alpha, version 6 of IBM's xlc compiler for AIX, Intel's icc
|
||||
versions 5-7, and Sun WorkShop cc version 6.
|
||||
|
||||
FFTW is likely to push compilers to their limits, however, and several
|
||||
compiler bugs have been exposed by FFTW. A partial list follows.
|
||||
|
||||
gcc 2.95.x for Solaris/SPARC produces incorrect code for the test program
|
||||
(workaround: recompile the libbench2 directory with -O2).
|
||||
|
||||
NetBSD/macppc 1.6 comes with a gcc version that also miscompiles the test
|
||||
program. (Please report a workaround if you know one.)
|
||||
|
||||
gcc 3.2.3 for ARM reportedly crashes during compilation. This bug is
|
||||
reportedly fixed in later versions of gcc.
|
||||
|
||||
Versions 8.0 and 8.1 of Intel's icc falsely claim to be gcc, so you should
|
||||
specify CC="icc -no-gcc"; this is automatic in FFTW 3.1. icc-8.0.066
|
||||
reportely produces incorrect code for FFTW 2.1.5, but is fixed in version
|
||||
8.1. icc-7.1 compiler build 20030402Z appears to produce incorrect
|
||||
dependencies, causing the compilation to fail. icc-7.1 build 20030307Z
|
||||
appears to work fine. (Use icc -V to check which build you have.) As of
|
||||
2003/04/18, build 20030402Z appears not to be available any longer on
|
||||
Intel's website, whereas the older build 20030307Z is available.
|
||||
|
||||
ranlib of GNU binutils 2.9.1 on Irix has been observed to corrupt the FFTW
|
||||
libraries, causing a link failure when FFTW is compiled. Since ranlib is
|
||||
completely superfluous on Irix, we suggest deleting it from your system
|
||||
and replacing it with a symbolic link to /bin/echo.
|
||||
|
||||
If support for SIMD instructions is enabled in FFTW, further compiler
|
||||
problems may appear:
|
||||
|
||||
gcc 3.4.[0123] for x86 produces incorrect SSE2 code for FFTW when -O2 (the
|
||||
best choice for FFTW) is used, causing FFTW to crash (make check crashes).
|
||||
This bug is fixed in gcc 3.4.4. On x86_64 (amd64/em64t), gcc 3.4.4
|
||||
reportedly still has a similar problem, but this is fixed as of gcc 3.4.6.
|
||||
|
||||
gcc-3.2 for x86 produces incorrect SIMD code if -O3 is used. The same
|
||||
compiler produces incorrect SIMD code if no optimization is used, too.
|
||||
When using gcc-3.2, it is a good idea not to change the default CFLAGS
|
||||
selected by the configure script.
|
||||
|
||||
Some 3.0.x and 3.1.x versions of gcc on x86 may crash. gcc so-called 2.96
|
||||
shipping with RedHat 7.3 crashes when compiling SIMD code. In both cases,
|
||||
please upgrade to gcc-3.2 or later.
|
||||
|
||||
Intel's icc 6.0 misaligns SSE constants, but FFTW has a workaround. icc
|
||||
8.x fails to compile FFTW 3.0.x because it falsely claims to be gcc; we
|
||||
believe this to be a bug in icc, but FFTW 3.1 has a workaround.
|
||||
|
||||
Visual C++ 2003 reportedly produces incorrect code for SSE/SSE2 when
|
||||
compiling FFTW. This bug was reportedly fixed in VC++ 2005;
|
||||
alternatively, you could switch to the Intel compiler. VC++ 6.0 also
|
||||
reportedly produces incorrect code for the file reodft11e-r2hc-odd.c
|
||||
unless optimizations are disabled for that file.
|
||||
|
||||
gcc 2.95 on MacOS X miscompiles AltiVec code (fixed in later versions).
|
||||
gcc 3.2.x miscompiles AltiVec permutations, but FFTW has a workaround.
|
||||
gcc 4.0.1 on MacOS for Intel crashes when compiling FFTW; a workaround is
|
||||
to compile one file without optimization: cd kernel; make CFLAGS=" "
|
||||
trig.lo.
|
||||
|
||||
gcc 4.1.1 reportedly crashes when compiling FFTW for MIPS; the workaround
|
||||
is to compile the file it crashes on (t2_64.c) with a lower optimization
|
||||
level.
|
||||
|
||||
gcc versions 4.1.2 to 4.2.0 for x86 reportedly miscompile FFTW 3.1's test
|
||||
program, causing make check to crash (gcc bug #26528). The bug was
|
||||
reportedly fixed in gcc version 4.2.1 and later. A workaround is to
|
||||
compile libbench2/verify-lib.c without optimization.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.4. FFTW does not compile on Solaris, complaining about const.
|
||||
|
||||
We know that at least on Solaris 2.5.x with Sun's compilers 4.2 you might
|
||||
get error messages from make such as
|
||||
|
||||
"./fftw.h", line 88: warning: const is a keyword in ANSI C
|
||||
|
||||
This is the case when the configure script reports that const does not
|
||||
work:
|
||||
|
||||
checking for working const... (cached) no
|
||||
|
||||
You should be aware that Solaris comes with two compilers, namely,
|
||||
/opt/SUNWspro/SC4.2/bin/cc and /usr/ucb/cc. The latter compiler is
|
||||
non-ANSI. Indeed, it is a perverse shell script that calls the real
|
||||
compiler in non-ANSI mode. In order to compile FFTW, change your path so
|
||||
that the right cc is used.
|
||||
|
||||
To know whether your compiler is the right one, type cc -V. If the
|
||||
compiler prints ``ucbcc'', as in
|
||||
|
||||
ucbcc: WorkShop Compilers 4.2 30 Oct 1996 C 4.2
|
||||
|
||||
then the compiler is wrong. The right message is something like
|
||||
|
||||
cc: WorkShop Compilers 4.2 30 Oct 1996 C 4.2
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.5. What's the difference between --enable-3dnow and --enable-k7?
|
||||
|
||||
--enable-k7 enables 3DNow! instructions on K7 processors (AMD Athlon and
|
||||
its variants). K7 support is provided by assembly routines generated by a
|
||||
special purpose compiler. As of fftw-3.2, --enable-k7 is no longer
|
||||
supported.
|
||||
|
||||
--enable-3dnow enables generic 3DNow! support using gcc builtin functions.
|
||||
This works on earlier AMD processors, but it is not as fast as our special
|
||||
assembly routines. As of fftw-3.1, --enable-3dnow is no longer supported.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.6. What's the difference between the fma and the non-fma versions?
|
||||
|
||||
The fma version tries to exploit the fused multiply-add instructions
|
||||
implemented in many processors such as PowerPC, ia-64, and MIPS. The two
|
||||
FFTW packages are otherwise identical. In FFTW 3.1, the fma and non-fma
|
||||
versions were merged together into a single package, and the configure
|
||||
script attempts to automatically guess which version to use.
|
||||
|
||||
The FFTW 3.1 configure script enables fma by default on PowerPC, Itanium,
|
||||
and PA-RISC, and disables it otherwise. You can force one or the other by
|
||||
using the --enable-fma or --disable-fma flag for configure.
|
||||
|
||||
Definitely use fma if you have a PowerPC-based system with gcc (or IBM
|
||||
xlc). This includes all GNU/Linux systems for PowerPC and the older
|
||||
PowerPC-based MacOS systems. Also use it on PA-RISC and Itanium with the
|
||||
HP/UX compiler.
|
||||
|
||||
Definitely do not use the fma version if you have an ia-32 processor
|
||||
(Intel, AMD, MacOS on Intel, etcetera).
|
||||
|
||||
For other architectures/compilers, the situation is not so clear. For
|
||||
example, ia-64 has the fma instruction, but gcc-3.2 appears not to exploit
|
||||
it correctly. Other compilers may do the right thing, but we have not
|
||||
tried them. Please send us your feedback so that we can update this FAQ
|
||||
entry.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.7. Which language is FFTW written in?
|
||||
|
||||
FFTW is written in ANSI C. Most of the code, however, was automatically
|
||||
generated by a program called genfft, written in the Objective Caml
|
||||
dialect of ML. You do not need to know ML or to have an Objective Caml
|
||||
compiler in order to use FFTW.
|
||||
|
||||
genfft is provided with the FFTW sources, which means that you can play
|
||||
with the code generator if you want. In this case, you need a working
|
||||
Objective Caml system. Objective Caml is available from the Caml web
|
||||
page.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.8. Can I call FFTW from Fortran?
|
||||
|
||||
Yes, FFTW (versions 1.3 and higher) contains a Fortran-callable interface,
|
||||
documented in the FFTW manual.
|
||||
|
||||
By default, FFTW configures its Fortran interface to work with the first
|
||||
compiler it finds, e.g. g77. To configure for a different, incompatible
|
||||
Fortran compiler foobar, use ./configure F77=foobar when installing FFTW.
|
||||
(In the case of g77, however, FFTW 3.x also includes an extra set of
|
||||
Fortran-callable routines with one less underscore at the end of
|
||||
identifiers, which should cover most other Fortran compilers on Linux at
|
||||
least.)
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.9. Can I call FFTW from C++?
|
||||
|
||||
Most definitely. FFTW should compile and/or link under any C++ compiler.
|
||||
Moreover, it is likely that the C++ <complex> template class is
|
||||
bit-compatible with FFTW's complex-number format (see the FFTW manual for
|
||||
more details).
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.10. Why isn't FFTW written in Fortran/C++?
|
||||
|
||||
Because we don't like those languages, and neither approaches the
|
||||
portability of C.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.11. How do I compile FFTW to run in single precision?
|
||||
|
||||
On a Unix system: configure --enable-float. On a non-Unix system: edit
|
||||
config.h to #define the symbol FFTW_SINGLE (for FFTW 3.x). In both cases,
|
||||
you must then recompile FFTW. In FFTW 3, all FFTW identifiers will then
|
||||
begin with fftwf_ instead of fftw_.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 2.12. --enable-k7 does not work on x86-64
|
||||
|
||||
Support for --enable-k7 was discontinued in fftw-3.2.
|
||||
|
||||
The fftw-3.1 release supports --enable-k7. This option only works on
|
||||
32-bit x86 machines that implement 3DNow!, including the AMD Athlon and
|
||||
the AMD Opteron in 32-bit mode. --enable-k7 does not work on AMD Opteron
|
||||
in 64-bit mode. Use --enable-sse for x86-64 machines.
|
||||
|
||||
FFTW supports 3DNow! by means of assembly code generated by a
|
||||
special-purpose compiler. It is hard to produce assembly code that works
|
||||
in both 32-bit and 64-bit mode.
|
||||
|
||||
===============================================================================
|
||||
|
||||
Section 3. Using FFTW
|
||||
|
||||
Q3.1 Why not support the FFTW 2 interface in FFTW 3?
|
||||
Q3.2 Why do FFTW 3 plans encapsulate the input/output arrays and not ju
|
||||
Q3.3 FFTW seems really slow.
|
||||
Q3.4 FFTW slows down after repeated calls.
|
||||
Q3.5 An FFTW routine is crashing when I call it.
|
||||
Q3.6 My Fortran program crashes when calling FFTW.
|
||||
Q3.7 FFTW gives results different from my old FFT.
|
||||
Q3.8 FFTW gives different results between runs
|
||||
Q3.9 Can I save FFTW's plans?
|
||||
Q3.10 Why does your inverse transform return a scaled result?
|
||||
Q3.11 How can I make FFTW put the origin (zero frequency) at the center
|
||||
Q3.12 How do I FFT an image/audio file in *foobar* format?
|
||||
Q3.13 My program does not link (on Unix).
|
||||
Q3.14 I included your header, but linking still fails.
|
||||
Q3.15 My program crashes, complaining about stack space.
|
||||
Q3.16 FFTW seems to have a memory leak.
|
||||
Q3.17 The output of FFTW's transform is all zeros.
|
||||
Q3.18 How do I call FFTW from the Microsoft language du jour?
|
||||
Q3.19 Can I compute only a subset of the DFT outputs?
|
||||
Q3.20 Can I use FFTW's routines for in-place and out-of-place matrix tra
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.1. Why not support the FFTW 2 interface in FFTW 3?
|
||||
|
||||
FFTW 3 has semantics incompatible with earlier versions: its plans can
|
||||
only be used for a given stride, multiplicity, and other characteristics
|
||||
of the input and output arrays; these stronger semantics are necessary for
|
||||
performance reasons. Thus, it is impossible to efficiently emulate the
|
||||
older interface (whose plans can be used for any transform of the same
|
||||
size). We believe that it should be possible to upgrade most programs
|
||||
without any difficulty, however.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.2. Why do FFTW 3 plans encapsulate the input/output arrays and not just the algorithm?
|
||||
|
||||
There are several reasons:
|
||||
|
||||
* It was important for performance reasons that the plan be specific to
|
||||
array characteristics like the stride (and alignment, for SIMD), and
|
||||
requiring that the user maintain these invariants is error prone.
|
||||
* In most high-performance applications, as far as we can tell, you are
|
||||
usually transforming the same array over and over, so FFTW's semantics
|
||||
should not be a burden.
|
||||
* If you need to transform another array of the same size, creating a new
|
||||
plan once the first exists is a cheap operation.
|
||||
* If you need to transform many arrays of the same size at once, you
|
||||
should really use the plan_many routines in FFTW's "advanced" interface.
|
||||
* If the abovementioned array characteristics are the same, you are
|
||||
willing to pay close attention to the documentation, and you really need
|
||||
to, we provide a "new-array execution" interface to apply a plan to a
|
||||
new array.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.3. FFTW seems really slow.
|
||||
|
||||
You are probably recreating the plan before every transform, rather than
|
||||
creating it once and reusing it for all transforms of the same size. FFTW
|
||||
is designed to be used in the following way:
|
||||
|
||||
* First, you create a plan. This will take several seconds.
|
||||
* Then, you reuse the plan many times to perform FFTs. These are fast.
|
||||
|
||||
If you don't need to compute many transforms and the time for the planner
|
||||
is significant, you have two options. First, you can use the
|
||||
FFTW_ESTIMATE option in the planner, which uses heuristics instead of
|
||||
runtime measurements and produces a good plan in a short time. Second,
|
||||
you can use the wisdom feature to precompute the plan; see Q3.9 `Can I
|
||||
save FFTW's plans?'
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.4. FFTW slows down after repeated calls.
|
||||
|
||||
Probably, NaNs or similar are creeping into your data, and the slowdown is
|
||||
due to the resulting floating-point exceptions. For example, be aware
|
||||
that repeatedly FFTing the same array is a diverging process (because FFTW
|
||||
computes the unnormalized transform).
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.5. An FFTW routine is crashing when I call it.
|
||||
|
||||
Did the FFTW test programs pass (make check, or cd tests; make bigcheck if
|
||||
you want to be paranoid)? If so, you almost certainly have a bug in your
|
||||
own code. For example, you could be passing invalid arguments (such as
|
||||
wrongly-sized arrays) to FFTW, or you could simply have memory corruption
|
||||
elsewhere in your program that causes random crashes later on. Please
|
||||
don't complain to us unless you can come up with a minimal self-contained
|
||||
program (preferably under 30 lines) that illustrates the problem.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.6. My Fortran program crashes when calling FFTW.
|
||||
|
||||
As described in the manual, on 64-bit machines you must store the plans in
|
||||
variables large enough to hold a pointer, for example integer*8. We
|
||||
recommend using integer*8 on 32-bit machines as well, to simplify porting.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.7. FFTW gives results different from my old FFT.
|
||||
|
||||
People follow many different conventions for the DFT, and you should be
|
||||
sure to know the ones that we use (described in the FFTW manual). In
|
||||
particular, you should be aware that the FFTW_FORWARD/FFTW_BACKWARD
|
||||
directions correspond to signs of -1/+1 in the exponent of the DFT
|
||||
definition. (*Numerical Recipes* uses the opposite convention.)
|
||||
|
||||
You should also know that we compute an unnormalized transform. In
|
||||
contrast, Matlab is an example of program that computes a normalized
|
||||
transform. See Q3.10 `Why does your inverse transform return a scaled
|
||||
result?'.
|
||||
|
||||
Finally, note that floating-point arithmetic is not exact, so different
|
||||
FFT algorithms will give slightly different results (on the order of the
|
||||
numerical accuracy; typically a fractional difference of 1e-15 or so in
|
||||
double precision).
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.8. FFTW gives different results between runs
|
||||
|
||||
If you use FFTW_MEASURE or FFTW_PATIENT mode, then the algorithm FFTW
|
||||
employs is not deterministic: it depends on runtime performance
|
||||
measurements. This will cause the results to vary slightly from run to
|
||||
run. However, the differences should be slight, on the order of the
|
||||
floating-point precision, and therefore should have no practical impact on
|
||||
most applications.
|
||||
|
||||
If you use saved plans (wisdom) or FFTW_ESTIMATE mode, however, then the
|
||||
algorithm is deterministic and the results should be identical between
|
||||
runs.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.9. Can I save FFTW's plans?
|
||||
|
||||
Yes. Starting with version 1.2, FFTW provides the wisdom mechanism for
|
||||
saving plans; see the FFTW manual.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.10. Why does your inverse transform return a scaled result?
|
||||
|
||||
Computing the forward transform followed by the backward transform (or
|
||||
vice versa) yields the original array scaled by the size of the array.
|
||||
(For multi-dimensional transforms, the size of the array is the product of
|
||||
the dimensions.) We could, instead, have chosen a normalization that
|
||||
would have returned the unscaled array. Or, to accomodate the many
|
||||
conventions in this matter, the transform routines could have accepted a
|
||||
"scale factor" parameter. We did not do this, however, for two reasons.
|
||||
First, we didn't want to sacrifice performance in the common case where
|
||||
the scale factor is 1. Second, in real applications the FFT is followed or
|
||||
preceded by some computation on the data, into which the scale factor can
|
||||
typically be absorbed at little or no cost.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.11. How can I make FFTW put the origin (zero frequency) at the center of its output?
|
||||
|
||||
For human viewing of a spectrum, it is often convenient to put the origin
|
||||
in frequency space at the center of the output array, rather than in the
|
||||
zero-th element (the default in FFTW). If all of the dimensions of your
|
||||
array are even, you can accomplish this by simply multiplying each element
|
||||
of the input array by (-1)^(i + j + ...), where i, j, etcetera are the
|
||||
indices of the element. (This trick is a general property of the DFT, and
|
||||
is not specific to FFTW.)
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.12. How do I FFT an image/audio file in *foobar* format?
|
||||
|
||||
FFTW performs an FFT on an array of floating-point values. You can
|
||||
certainly use it to compute the transform of an image or audio stream, but
|
||||
you are responsible for figuring out your data format and converting it to
|
||||
the form FFTW requires.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.13. My program does not link (on Unix).
|
||||
|
||||
The libraries must be listed in the correct order (-lfftw3 -lm for FFTW
|
||||
3.x) and *after* your program sources/objects. (The general rule is that
|
||||
if *A* uses *B*, then *A* must be listed before *B* in the link command.).
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.14. I included your header, but linking still fails.
|
||||
|
||||
You're a C++ programmer, aren't you? You have to compile the FFTW library
|
||||
and link it into your program, not just #include <fftw3.h>. (Yes, this is
|
||||
really a FAQ.)
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.15. My program crashes, complaining about stack space.
|
||||
|
||||
You cannot declare large arrays with automatic storage (e.g. via
|
||||
fftw_complex array[N]); you should use fftw_malloc (or equivalent) to
|
||||
allocate the arrays you want to transform if they are larger than a few
|
||||
hundred elements.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.16. FFTW seems to have a memory leak.
|
||||
|
||||
After you create a plan, FFTW caches the information required to quickly
|
||||
recreate the plan. (See Q3.9 `Can I save FFTW's plans?') It also
|
||||
maintains a small amount of other persistent memory. You can deallocate
|
||||
all of FFTW's internally allocated memory, if you wish, by calling
|
||||
fftw_cleanup(), as documented in the manual.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.17. The output of FFTW's transform is all zeros.
|
||||
|
||||
You should initialize your input array *after* creating the plan, unless
|
||||
you use FFTW_ESTIMATE: planning with FFTW_MEASURE or FFTW_PATIENT
|
||||
overwrites the input/output arrays, as described in the manual.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.18. How do I call FFTW from the Microsoft language du jour?
|
||||
|
||||
Please *do not* ask us Windows-specific questions. We do not use Windows.
|
||||
We know nothing about Visual Basic, Visual C++, or .NET. Please find the
|
||||
appropriate Usenet discussion group and ask your question there. See also
|
||||
Q2.2 `Does FFTW run on Windows?'.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.19. Can I compute only a subset of the DFT outputs?
|
||||
|
||||
In general, no, an FFT intrinsically computes all outputs from all inputs.
|
||||
In principle, there is something called a *pruned FFT* that can do what
|
||||
you want, but to compute K outputs out of N the complexity is in general
|
||||
O(N log K) instead of O(N log N), thus saving only a small additive factor
|
||||
in the log. (The same argument holds if you instead have only K nonzero
|
||||
inputs.)
|
||||
|
||||
There are some specific cases in which you can get the O(N log K)
|
||||
performance benefits easily, however, by combining a few ordinary FFTs.
|
||||
In particular, the case where you want the first K outputs, where K
|
||||
divides N, can be handled by performing N/K transforms of size K and then
|
||||
summing the outputs multiplied by appropriate phase factors. For more
|
||||
details, see pruned FFTs with FFTW.
|
||||
|
||||
There are also some algorithms that compute pruned transforms
|
||||
*approximately*, but they are beyond the scope of this FAQ.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 3.20. Can I use FFTW's routines for in-place and out-of-place matrix transposition?
|
||||
|
||||
You can use the FFTW guru interface to create a rank-0 transform of vector
|
||||
rank 2 where the vector strides are transposed. (A rank-0 transform is
|
||||
equivalent to a 1D transform of size 1, which. just copies the input into
|
||||
the output.) Specifying the same location for the input and output makes
|
||||
the transpose in-place.
|
||||
|
||||
For double-valued data stored in row-major format, plan creation looks
|
||||
like this:
|
||||
|
||||
fftw_plan plan_transpose(int rows, int cols, double *in, double *out)
|
||||
{
|
||||
const unsigned flags = FFTW_ESTIMATE; /* other flags are possible */
|
||||
fftw_iodim howmany_dims[2];
|
||||
|
||||
howmany_dims[0].n = rows;
|
||||
howmany_dims[0].is = cols;
|
||||
howmany_dims[0].os = 1;
|
||||
|
||||
howmany_dims[1].n = cols;
|
||||
howmany_dims[1].is = 1;
|
||||
howmany_dims[1].os = rows;
|
||||
|
||||
return fftw_plan_guru_r2r(/*rank=*/ 0, /*dims=*/ NULL,
|
||||
/*howmany_rank=*/ 2, howmany_dims,
|
||||
in, out, /*kind=*/ NULL, flags);
|
||||
}
|
||||
(This entry was written by Rhys Ulerich.)
|
||||
|
||||
===============================================================================
|
||||
|
||||
Section 4. Internals of FFTW
|
||||
|
||||
Q4.1 How does FFTW work?
|
||||
Q4.2 Why is FFTW so fast?
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 4.1. How does FFTW work?
|
||||
|
||||
The innovation (if it can be so called) in FFTW consists in having a
|
||||
variety of composable *solvers*, representing different FFT algorithms and
|
||||
implementation strategies, whose combination into a particular *plan* for
|
||||
a given size can be determined at runtime according to the characteristics
|
||||
of your machine/compiler. This peculiar software architecture allows FFTW
|
||||
to adapt itself to almost any machine.
|
||||
|
||||
For more details (albeit somewhat outdated), see the paper "FFTW: An
|
||||
Adaptive Software Architecture for the FFT", by M. Frigo and S. G.
|
||||
Johnson, *Proc. ICASSP* 3, 1381 (1998), also available at the FFTW web
|
||||
page.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 4.2. Why is FFTW so fast?
|
||||
|
||||
This is a complex question, and there is no simple answer. In fact, the
|
||||
authors do not fully know the answer, either. In addition to many small
|
||||
performance hacks throughout FFTW, there are three general reasons for
|
||||
FFTW's speed.
|
||||
|
||||
* FFTW uses a variety of FFT algorithms and implementation styles that
|
||||
can be arbitrarily composed to adapt itself to a machine. See Q4.1 `How
|
||||
does FFTW work?'.
|
||||
* FFTW uses a code generator to produce highly-optimized routines for
|
||||
computing small transforms.
|
||||
* FFTW uses explicit divide-and-conquer to take advantage of the memory
|
||||
hierarchy.
|
||||
|
||||
For more details (albeit somewhat outdated), see the paper "FFTW: An
|
||||
Adaptive Software Architecture for the FFT", by M. Frigo and S. G.
|
||||
Johnson, *Proc. ICASSP* 3, 1381 (1998), available along with other
|
||||
references at the FFTW web page.
|
||||
|
||||
===============================================================================
|
||||
|
||||
Section 5. Known bugs
|
||||
|
||||
Q5.1 FFTW 1.1 crashes in rfftwnd on Linux.
|
||||
Q5.2 The MPI transforms in FFTW 1.2 give incorrect results/leak memory.
|
||||
Q5.3 The test programs in FFTW 1.2.1 fail when I change FFTW to use sin
|
||||
Q5.4 The test program in FFTW 1.2.1 fails for n > 46340.
|
||||
Q5.5 The threaded code fails on Linux Redhat 5.0
|
||||
Q5.6 FFTW 2.0's rfftwnd fails for rank > 1 transforms with a final dime
|
||||
Q5.7 FFTW 2.0's complex transforms give the wrong results with prime fa
|
||||
Q5.8 FFTW 2.1.1's MPI test programs crash with MPICH.
|
||||
Q5.9 FFTW 2.1.2's multi-threaded transforms don't work on AIX.
|
||||
Q5.10 FFTW 2.1.2's complex transforms give incorrect results for large p
|
||||
Q5.11 FFTW 2.1.3's multi-threaded transforms don't give any speedup on S
|
||||
Q5.12 FFTW 2.1.3 crashes on AIX.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.1. FFTW 1.1 crashes in rfftwnd on Linux.
|
||||
|
||||
This bug was fixed in FFTW 1.2. There was a bug in rfftwnd causing an
|
||||
incorrect amount of memory to be allocated. The bug showed up in Linux
|
||||
with libc-5.3.12 (and nowhere else that we know of).
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.2. The MPI transforms in FFTW 1.2 give incorrect results/leak memory.
|
||||
|
||||
These bugs were corrected in FFTW 1.2.1. The MPI transforms (really, just
|
||||
the transpose routines) in FFTW 1.2 had bugs that could cause errors in
|
||||
some situations.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.3. The test programs in FFTW 1.2.1 fail when I change FFTW to use single precision.
|
||||
|
||||
This bug was fixed in FFTW 1.3. (Older versions of FFTW did work in
|
||||
single precision, but the test programs didn't--the error tolerances in
|
||||
the tests were set for double precision.)
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.4. The test program in FFTW 1.2.1 fails for n > 46340.
|
||||
|
||||
This bug was fixed in FFTW 1.3. FFTW 1.2.1 produced the right answer, but
|
||||
the test program was wrong. For large n, n*n in the naive transform that
|
||||
we used for comparison overflows 32 bit integer precision, breaking the
|
||||
test.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.5. The threaded code fails on Linux Redhat 5.0
|
||||
|
||||
We had problems with glibc-2.0.5. The code should work with glibc-2.0.7.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.6. FFTW 2.0's rfftwnd fails for rank > 1 transforms with a final dimension >= 65536.
|
||||
|
||||
This bug was fixed in FFTW 2.0.1. (There was a 32-bit integer overflow
|
||||
due to a poorly-parenthesized expression.)
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.7. FFTW 2.0's complex transforms give the wrong results with prime factors 17 to 97.
|
||||
|
||||
There was a bug in the complex transforms that could cause incorrect
|
||||
results under (hopefully rare) circumstances for lengths with
|
||||
intermediate-size prime factors (17-97). This bug was fixed in FFTW
|
||||
2.1.1.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.8. FFTW 2.1.1's MPI test programs crash with MPICH.
|
||||
|
||||
This bug was fixed in FFTW 2.1.2. The 2.1/2.1.1 MPI test programs crashed
|
||||
when using the MPICH implementation of MPI with the ch_p4 device (TCP/IP);
|
||||
the transforms themselves worked fine.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.9. FFTW 2.1.2's multi-threaded transforms don't work on AIX.
|
||||
|
||||
This bug was fixed in FFTW 2.1.3. The multi-threaded transforms in
|
||||
previous versions didn't work with AIX's pthreads implementation, which
|
||||
idiosyncratically creates threads in detached (non-joinable) mode by
|
||||
default.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.10. FFTW 2.1.2's complex transforms give incorrect results for large prime sizes.
|
||||
|
||||
This bug was fixed in FFTW 2.1.3. FFTW's complex-transform algorithm for
|
||||
prime sizes (in versions 2.0 to 2.1.2) had an integer overflow problem
|
||||
that caused incorrect results for many primes greater than 32768 (on
|
||||
32-bit machines). (Sizes without large prime factors are not affected.)
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.11. FFTW 2.1.3's multi-threaded transforms don't give any speedup on Solaris.
|
||||
|
||||
This bug was fixed in FFTW 2.1.4. (By default, Solaris creates threads
|
||||
that do not parallelize over multiple processors, so one has to request
|
||||
the proper behavior specifically.)
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Question 5.12. FFTW 2.1.3 crashes on AIX.
|
||||
|
||||
The FFTW 2.1.3 configure script picked incorrect compiler flags for the
|
||||
xlc compiler on newer IBM processors. This is fixed in FFTW 2.1.4.
|
||||
|
||||
708
fftw-3.3.10/doc/FAQ/fftw-faq.bfnn
Normal file
708
fftw-3.3.10/doc/FAQ/fftw-faq.bfnn
Normal file
@@ -0,0 +1,708 @@
|
||||
\comment This is the source for the FFTW FAQ list, in
|
||||
\comment the Bizarre Format With No Name. It is turned into Lout
|
||||
\comment input, HTML, plain ASCII and an Info document by a Perl script.
|
||||
\comment
|
||||
\comment The format and scripts come from the Linux FAQ, by
|
||||
\comment Ian Jackson.
|
||||
\set brieftitle FFTW FAQ
|
||||
\set author <A href="http://www.fftw.org">Matteo Frigo and Steven G. Johnson</A> / <A href="mailto:fftw@fftw.org">fftw@fftw.org</A>
|
||||
\set authormail fftw@fftw.org
|
||||
\set title FFTW Frequently Asked Questions with Answers
|
||||
\set copyholder Matteo Frigo and Massachusetts Institute of Technology
|
||||
\call-html startup html.refs2
|
||||
\copyto ASCII
|
||||
FFTW FREQUENTLY ASKED QUESTIONS WITH ANSWERS
|
||||
`date '+%d %h %Y'`
|
||||
Matteo Frigo
|
||||
Steven G. Johnson
|
||||
<fftw@fftw.org>
|
||||
|
||||
\endcopy
|
||||
\copyto INFO
|
||||
INFO-DIR-SECTION Development
|
||||
START-INFO-DIR-ENTRY
|
||||
* FFTW FAQ: (fftw-faq). FFTW Frequently Asked Questions with Answers.
|
||||
END-INFO-DIR-ENTRY
|
||||
|
||||
|
||||
File: $prefix.info, Node: Top, Next: Question 1.1, Up: (dir)
|
||||
|
||||
FFTW FREQUENTLY ASKED QUESTIONS WITH ANSWERS
|
||||
`date '+%d %h %Y'`
|
||||
Matteo Frigo
|
||||
Steven G. Johnson
|
||||
<fftw@fftw.org>
|
||||
|
||||
\endcopy
|
||||
|
||||
This is the list of Frequently Asked Questions about FFTW, a
|
||||
collection of fast C routines for computing the Discrete Fourier
|
||||
Transform in one or more dimensions.
|
||||
|
||||
\section Index
|
||||
|
||||
\index
|
||||
|
||||
\comment ######################################################################
|
||||
|
||||
\section Introduction and General Information
|
||||
|
||||
\question 26aug:whatisfftw What is FFTW?
|
||||
|
||||
FFTW is a free collection of fast C routines for computing the
|
||||
Discrete Fourier Transform in one or more dimensions. It includes
|
||||
complex, real, symmetric, and parallel transforms, and can handle
|
||||
arbitrary array sizes efficiently. FFTW is typically faster than
|
||||
other publically-available FFT implementations, and is even
|
||||
competitive with vendor-tuned libraries. (See our web page for
|
||||
extensive benchmarks.) To achieve this performance, FFTW uses novel
|
||||
code-generation and runtime self-optimization techniques (along with
|
||||
many other tricks).
|
||||
|
||||
\question 26aug:whereisfftw How do I obtain FFTW?
|
||||
|
||||
FFTW can be found at \docref{the FFTW web page\}. You can also
|
||||
retrieve it from \ftpon ftp.fftw.org in \ftpin /pub/fftw.
|
||||
|
||||
\question 26aug:isfftwfree Is FFTW free software?
|
||||
|
||||
Starting with version 1.3, FFTW is Free Software in the technical
|
||||
sense defined by the Free Software Foundation (see \docref{Categories
|
||||
of Free and Non-Free Software\}), and is distributed under the terms
|
||||
of the GNU General Public License. Previous versions of FFTW were
|
||||
distributed without fee for noncommercial use, but were not
|
||||
technically ``free.''
|
||||
|
||||
Non-free licenses for FFTW are also available that permit different
|
||||
terms of use than the GPL.
|
||||
|
||||
\question 10apr:nonfree What is this about non-free licenses?
|
||||
|
||||
The non-free licenses are for companies that wish to use FFTW in their
|
||||
products but are unwilling to release their software under the GPL
|
||||
(which would require them to release source code and allow free
|
||||
redistribution). Such users can purchase an unlimited-use license
|
||||
from MIT. Contact us for more details.
|
||||
|
||||
We could instead have released FFTW under the LGPL, or even disallowed
|
||||
non-Free usage. Suffice it to say, however, that MIT owns the
|
||||
copyright to FFTW and they only let us GPL it because we convinced
|
||||
them that it would neither affect their licensing revenue nor irritate
|
||||
existing licensees.
|
||||
|
||||
\question 24oct:west In the West? I thought MIT was in the East?
|
||||
|
||||
Not to an Italian. You could say that we're a Spaghetti Western
|
||||
(with apologies to Sergio Leone).
|
||||
|
||||
\comment ######################################################################
|
||||
|
||||
\section Installing FFTW
|
||||
|
||||
\question 26aug:systems Which systems does FFTW run on?
|
||||
|
||||
FFTW is written in ANSI C, and should work on any system with a decent
|
||||
C compiler. (See also \qref runOnWindows, \qref compilerCrashes.)
|
||||
FFTW can also take advantage of certain hardware-specific features,
|
||||
such as cycle counters and SIMD instructions, but this is optional.
|
||||
|
||||
\question 26aug:runOnWindows Does FFTW run on Windows?
|
||||
|
||||
Yes, many people have reported successfully using FFTW on Windows with
|
||||
various compilers. FFTW was not developed on Windows, but the source
|
||||
code is essentially straight ANSI C. See also the \docref{FFTW
|
||||
Windows installation notes\}, \qref compilerCrashes, and \qref
|
||||
vbetalia.
|
||||
|
||||
\question 26aug:compilerCrashes My compiler has trouble with FFTW.
|
||||
|
||||
Complain fiercely to the vendor of the compiler.
|
||||
|
||||
We have successfully used \courier{gcc\} 3.2.x on x86 and PPC, a
|
||||
recent Compaq C compiler for Alpha, version 6 of IBM's \courier{xlc\}
|
||||
compiler for AIX, Intel's \courier{icc\} versions 5-7, and Sun
|
||||
WorkShop \courier{cc\} version 6.
|
||||
|
||||
FFTW is likely to push compilers to their limits, however, and several
|
||||
compiler bugs have been exposed by FFTW. A partial list follows.
|
||||
|
||||
\courier{gcc\} 2.95.x for Solaris/SPARC produces incorrect code for
|
||||
the test program (workaround: recompile the \courier{libbench2\}
|
||||
directory with \courier{-O2\}).
|
||||
|
||||
NetBSD/macppc 1.6 comes with a \courier{gcc\} version that also
|
||||
miscompiles the test program. (Please report a workaround if you know
|
||||
one.)
|
||||
|
||||
\courier{gcc\} 3.2.3 for ARM reportedly crashes during compilation.
|
||||
This bug is reportedly fixed in later versions of \courier{gcc\}.
|
||||
|
||||
Versions 8.0 and 8.1 of Intel's \courier{icc\} falsely claim to be
|
||||
\courier{gcc\}, so you should specify \courier{CC="icc -no-gcc"\};
|
||||
this is automatic in FFTW 3.1. \courier{icc-8.0.066\} reportely
|
||||
produces incorrect code for FFTW 2.1.5, but is fixed in version 8.1.
|
||||
\courier{icc-7.1\} compiler build 20030402Z appears to produce
|
||||
incorrect dependencies, causing the compilation to fail.
|
||||
\courier{icc-7.1\} build 20030307Z appears to work fine. (Use
|
||||
\courier{icc -V\} to check which build you have.) As of 2003/04/18,
|
||||
build 20030402Z appears not to be available any longer on Intel's
|
||||
website, whereas the older build 20030307Z is available.
|
||||
|
||||
\courier{ranlib\} of GNU \courier{binutils\} 2.9.1 on Irix has been
|
||||
observed to corrupt the FFTW libraries, causing a link failure when
|
||||
FFTW is compiled. Since \courier{ranlib\} is completely superfluous
|
||||
on Irix, we suggest deleting it from your system and replacing it with
|
||||
a symbolic link to \courier{/bin/echo\}.
|
||||
|
||||
If support for SIMD instructions is enabled in FFTW, further compiler
|
||||
problems may appear:
|
||||
|
||||
\courier{gcc\} 3.4.[0123] for x86 produces incorrect SSE2 code for
|
||||
FFTW when \courier{-O2\} (the best choice for FFTW) is used, causing
|
||||
FFTW to crash (\courier{make check\} crashes). This bug is fixed in
|
||||
\courier{gcc\} 3.4.4. On x86_64 (amd64/em64t), \courier{gcc\} 3.4.4
|
||||
reportedly still has a similar problem, but this is fixed as of
|
||||
\courier{gcc\} 3.4.6.
|
||||
|
||||
\courier{gcc-3.2\} for x86 produces incorrect SIMD code if
|
||||
\courier{-O3\} is used. The same compiler produces incorrect SIMD
|
||||
code if no optimization is used, too. When using \courier{gcc-3.2\},
|
||||
it is a good idea not to change the default \courier{CFLAGS\} selected
|
||||
by the \courier{configure\} script.
|
||||
|
||||
Some 3.0.x and 3.1.x versions of \courier{gcc\} on \courier{x86\} may
|
||||
crash. \courier{gcc\} so-called 2.96 shipping with RedHat 7.3 crashes
|
||||
when compiling SIMD code. In both cases, please upgrade to
|
||||
\courier{gcc-3.2\} or later.
|
||||
|
||||
Intel's \courier{icc\} 6.0 misaligns SSE constants, but FFTW has a
|
||||
workaround. \courier{icc\} 8.x fails to compile FFTW 3.0.x because it
|
||||
falsely claims to be \courier{gcc\}; we believe this to be a bug in
|
||||
\courier{icc\}, but FFTW 3.1 has a workaround.
|
||||
|
||||
Visual C++ 2003 reportedly produces incorrect code for SSE/SSE2 when
|
||||
compiling FFTW. This bug was reportedly fixed in VC++ 2005;
|
||||
alternatively, you could switch to the Intel compiler. VC++ 6.0 also
|
||||
reportedly produces incorrect code for the file
|
||||
\courier{reodft11e-r2hc-odd.c\} unless optimizations are disabled for
|
||||
that file.
|
||||
|
||||
\courier{gcc\} 2.95 on MacOS X miscompiles AltiVec code (fixed in
|
||||
later versions). \courier{gcc\} 3.2.x miscompiles AltiVec
|
||||
permutations, but FFTW has a workaround. \courier{gcc\} 4.0.1 on
|
||||
MacOS for Intel crashes when compiling FFTW; a workaround is to
|
||||
compile one file without optimization: \courier{cd kernel; make
|
||||
CFLAGS=" " trig.lo\}.
|
||||
|
||||
\courier{gcc\} 4.1.1 reportedly crashes when compiling FFTW for MIPS;
|
||||
the workaround is to compile the file it crashes on
|
||||
(\courier{t2_64.c\}) with a lower optimization level.
|
||||
|
||||
\courier{gcc\} versions 4.1.2 to 4.2.0 for x86 reportedly miscompile
|
||||
FFTW 3.1's test program, causing \courier{make check\} to crash
|
||||
(\courier{gcc\} bug #26528). The bug was reportedly fixed in
|
||||
\courier{gcc\} version 4.2.1 and later. A workaround is to compile
|
||||
\courier{libbench2/verify-lib.c\} without optimization.
|
||||
|
||||
\question 26aug:solarisSucks FFTW does not compile on Solaris, complaining about \courier{const\}.
|
||||
|
||||
We know that at least on Solaris 2.5.x with Sun's compilers 4.2 you
|
||||
might get error messages from \courier{make\} such as
|
||||
|
||||
\courier{"./fftw.h", line 88: warning: const is a keyword in ANSI C\}
|
||||
|
||||
This is the case when the \courier{configure\} script reports that
|
||||
\courier{const\} does not work:
|
||||
|
||||
\courier{checking for working const... (cached) no\}
|
||||
|
||||
You should be aware that Solaris comes with two compilers, namely,
|
||||
\courier{/opt/SUNWspro/SC4.2/bin/cc\} and \courier{/usr/ucb/cc\}. The
|
||||
latter compiler is non-ANSI. Indeed, it is a perverse shell script
|
||||
that calls the real compiler in non-ANSI mode. In order
|
||||
to compile FFTW, change your path so that the right \courier{cc\}
|
||||
is used.
|
||||
|
||||
To know whether your compiler is the right one, type
|
||||
\courier{cc -V\}. If the compiler prints ``\courier{ucbcc\}'',
|
||||
as in
|
||||
|
||||
\courier{ucbcc: WorkShop Compilers 4.2 30 Oct 1996 C 4.2\}
|
||||
|
||||
then the compiler is wrong. The right message is something like
|
||||
|
||||
\courier{cc: WorkShop Compilers 4.2 30 Oct 1996 C 4.2\}
|
||||
|
||||
\question 19mar:3dnow What's the difference between \courier{--enable-3dnow\} and \courier{--enable-k7\}?
|
||||
|
||||
\courier{--enable-k7\} enables 3DNow! instructions on K7 processors
|
||||
(AMD Athlon and its variants). K7 support is provided by assembly
|
||||
routines generated by a special purpose compiler.
|
||||
As of fftw-3.2, --enable-k7 is no longer supported.
|
||||
|
||||
\courier{--enable-3dnow\} enables generic 3DNow! support using
|
||||
\courier{gcc\} builtin functions. This works on earlier AMD
|
||||
processors, but it is not as fast as our special assembly routines.
|
||||
As of fftw-3.1, --enable-3dnow is no longer supported.
|
||||
|
||||
\question 18apr:fma What's the difference between the fma and the non-fma versions?
|
||||
|
||||
The fma version tries to exploit the fused multiply-add instructions
|
||||
implemented in many processors such as PowerPC, ia-64, and MIPS. The
|
||||
two FFTW packages are otherwise identical. In FFTW 3.1, the fma and
|
||||
non-fma versions were merged together into a single package, and the
|
||||
\courier{configure\} script attempts to automatically guess which
|
||||
version to use.
|
||||
|
||||
The FFTW 3.1 \courier{configure\} script enables fma by default on
|
||||
PowerPC, Itanium, and PA-RISC, and disables it otherwise. You can
|
||||
force one or the other by using the \courier{--enable-fma\} or
|
||||
\courier{--disable-fma\} flag for \courier{configure\}.
|
||||
|
||||
Definitely use fma if you have a PowerPC-based system with
|
||||
\courier{gcc\} (or IBM \courier{xlc\}). This includes all GNU/Linux
|
||||
systems for PowerPC and the older PowerPC-based MacOS systems. Also
|
||||
use it on PA-RISC and Itanium with the HP/UX compiler.
|
||||
|
||||
Definitely do not use the fma version if you have an ia-32 processor
|
||||
(Intel, AMD, MacOS on Intel, etcetera).
|
||||
|
||||
For other architectures/compilers, the situation is not so clear. For
|
||||
example, ia-64 has the fma instruction, but \courier{gcc-3.2\} appears
|
||||
not to exploit it correctly. Other compilers may do the right thing,
|
||||
but we have not tried them. Please send us your feedback so that we
|
||||
can update this FAQ entry.
|
||||
|
||||
\question 26aug:languages Which language is FFTW written in?
|
||||
|
||||
FFTW is written in ANSI C. Most of the code, however, was
|
||||
automatically generated by a program called \courier{genfft\}, written
|
||||
in the Objective Caml dialect of ML. You do not need to know ML or to
|
||||
have an Objective Caml compiler in order to use FFTW.
|
||||
|
||||
\courier{genfft\} is provided with the FFTW sources, which means that
|
||||
you can play with the code generator if you want. In this case, you
|
||||
need a working Objective Caml system. Objective Caml is available
|
||||
from \docref{the Caml web page\}.
|
||||
|
||||
\question 26aug:fortran Can I call FFTW from Fortran?
|
||||
|
||||
Yes, FFTW (versions 1.3 and higher) contains a Fortran-callable
|
||||
interface, documented in the FFTW manual.
|
||||
|
||||
By default, FFTW configures its Fortran interface to work with the
|
||||
first compiler it finds, e.g. \courier{g77\}. To configure for a
|
||||
different, incompatible Fortran compiler \courier{foobar\}, use
|
||||
\courier{./configure F77=foobar\} when installing FFTW. (In the case
|
||||
of \courier{g77\}, however, FFTW 3.x also includes an extra set of
|
||||
Fortran-callable routines with one less underscore at the end of
|
||||
identifiers, which should cover most other Fortran compilers on Linux
|
||||
at least.)
|
||||
|
||||
\question 26aug:cplusplus Can I call FFTW from C++?
|
||||
|
||||
Most definitely. FFTW should compile and/or link under any C++
|
||||
compiler. Moreover, it is likely that the C++ \courier{<complex>\}
|
||||
template class is bit-compatible with FFTW's complex-number format
|
||||
(see the FFTW manual for more details).
|
||||
|
||||
\question 26aug:whynotfortran Why isn't FFTW written in Fortran/C++?
|
||||
|
||||
Because we don't like those languages, and neither approaches the
|
||||
portability of C.
|
||||
|
||||
\question 29mar:singleprec How do I compile FFTW to run in single precision?
|
||||
|
||||
On a Unix system: \courier{configure --enable-float\}. On a non-Unix
|
||||
system: edit \courier{config.h\} to \courier{#define\} the symbol
|
||||
\courier{FFTW_SINGLE\} (for FFTW 3.x). In both cases, you must then
|
||||
recompile FFTW. In FFTW 3, all FFTW identifiers will then begin with
|
||||
\courier{fftwf_\} instead of \courier{fftw_\}.
|
||||
|
||||
\question 28mar:64bitk7 --enable-k7 does not work on x86-64
|
||||
|
||||
Support for --enable-k7 was discontinued in fftw-3.2.
|
||||
|
||||
The fftw-3.1 release supports --enable-k7. This option only works on
|
||||
32-bit x86 machines that implement 3DNow!, including the AMD Athlon
|
||||
and the AMD Opteron in 32-bit mode. --enable-k7 does not work on AMD
|
||||
Opteron in 64-bit mode. Use --enable-sse for x86-64 machines.
|
||||
|
||||
FFTW supports 3DNow! by means of assembly code generated by a
|
||||
special-purpose compiler. It is hard to produce assembly code that
|
||||
works in both 32-bit and 64-bit mode.
|
||||
|
||||
\comment ######################################################################
|
||||
|
||||
\section Using FFTW
|
||||
|
||||
\question 15mar:fftw2to3 Why not support the FFTW 2 interface in FFTW 3?
|
||||
|
||||
FFTW 3 has semantics incompatible with earlier versions: its plans can
|
||||
only be used for a given stride, multiplicity, and other
|
||||
characteristics of the input and output arrays; these stronger
|
||||
semantics are necessary for performance reasons. Thus, it is
|
||||
impossible to efficiently emulate the older interface (whose plans can
|
||||
be used for any transform of the same size). We believe that it
|
||||
should be possible to upgrade most programs without any difficulty,
|
||||
however.
|
||||
|
||||
\question 20mar:planperarray Why do FFTW 3 plans encapsulate the input/output arrays and not just the algorithm?
|
||||
|
||||
There are several reasons:
|
||||
|
||||
\call startlist
|
||||
\call item
|
||||
It was important for performance reasons that the plan be specific to
|
||||
array characteristics like the stride (and alignment, for SIMD), and
|
||||
requiring that the user maintain these invariants is error prone.
|
||||
\call item
|
||||
In most high-performance applications, as far as we can tell, you are
|
||||
usually transforming the same array over and over, so FFTW's semantics
|
||||
should not be a burden.
|
||||
\call item
|
||||
If you need to transform another array of the same size, creating a
|
||||
new plan once the first exists is a cheap operation.
|
||||
\call item
|
||||
If you need to transform many arrays of the same size at once, you
|
||||
should really use the \courier{plan_many\} routines in FFTW's "advanced"
|
||||
interface.
|
||||
\call item
|
||||
If the abovementioned array characteristics are the same, you are
|
||||
willing to pay close attention to the documentation, and you really
|
||||
need to, we provide a "new-array execution" interface to apply a plan
|
||||
to a new array.
|
||||
\call endlist
|
||||
|
||||
\question 25may:slow FFTW seems really slow.
|
||||
|
||||
You are probably recreating the plan before every transform, rather
|
||||
than creating it once and reusing it for all transforms of the same
|
||||
size. FFTW is designed to be used in the following way:
|
||||
|
||||
\call startlist
|
||||
\call item
|
||||
First, you create a plan. This will take several seconds.
|
||||
\call item
|
||||
Then, you reuse the plan many times to perform FFTs. These are fast.
|
||||
\call endlist
|
||||
|
||||
If you don't need to compute many transforms and the time for the
|
||||
planner is significant, you have two options. First, you can use the
|
||||
\courier{FFTW_ESTIMATE\} option in the planner, which uses heuristics
|
||||
instead of runtime measurements and produces a good plan in a short
|
||||
time. Second, you can use the wisdom feature to precompute the plan;
|
||||
see \qref savePlans
|
||||
|
||||
\question 22oct:slows FFTW slows down after repeated calls.
|
||||
|
||||
Probably, NaNs or similar are creeping into your data, and the
|
||||
slowdown is due to the resulting floating-point exceptions. For
|
||||
example, be aware that repeatedly FFTing the same array is a diverging
|
||||
process (because FFTW computes the unnormalized transform).
|
||||
|
||||
\question 22oct:segfault An FFTW routine is crashing when I call it.
|
||||
|
||||
Did the FFTW test programs pass (\courier{make check\}, or \courier{cd
|
||||
tests; make bigcheck\} if you want to be paranoid)? If so, you almost
|
||||
certainly have a bug in your own code. For example, you could be
|
||||
passing invalid arguments (such as wrongly-sized arrays) to FFTW, or
|
||||
you could simply have memory corruption elsewhere in your program that
|
||||
causes random crashes later on. Please don't complain to us unless
|
||||
you can come up with a minimal self-contained program (preferably
|
||||
under 30 lines) that illustrates the problem.
|
||||
|
||||
\question 22oct:fortran64 My Fortran program crashes when calling FFTW.
|
||||
|
||||
As described in the manual, on 64-bit machines you must store the
|
||||
plans in variables large enough to hold a pointer, for example
|
||||
\courier{integer*8\}. We recommend using \courier{integer*8\} on
|
||||
32-bit machines as well, to simplify porting.
|
||||
|
||||
\question 24mar:conventions FFTW gives results different from my old FFT.
|
||||
|
||||
People follow many different conventions for the DFT, and you should
|
||||
be sure to know the ones that we use (described in the FFTW manual).
|
||||
In particular, you should be aware that the
|
||||
\courier{FFTW_FORWARD\}/\courier{FFTW_BACKWARD\} directions correspond
|
||||
to signs of -1/+1 in the exponent of the DFT definition.
|
||||
(\italic{Numerical Recipes\} uses the opposite convention.)
|
||||
|
||||
You should also know that we compute an unnormalized transform. In
|
||||
contrast, Matlab is an example of program that computes a normalized
|
||||
transform. See \qref whyscaled.
|
||||
|
||||
Finally, note that floating-point arithmetic is not exact, so
|
||||
different FFT algorithms will give slightly different results (on the
|
||||
order of the numerical accuracy; typically a fractional difference of
|
||||
1e-15 or so in double precision).
|
||||
|
||||
\question 31aug:nondeterministic FFTW gives different results between runs
|
||||
|
||||
If you use \courier{FFTW_MEASURE\} or \courier{FFTW_PATIENT\} mode,
|
||||
then the algorithm FFTW employs is not deterministic: it depends on
|
||||
runtime performance measurements. This will cause the results to vary
|
||||
slightly from run to run. However, the differences should be slight,
|
||||
on the order of the floating-point precision, and therefore should
|
||||
have no practical impact on most applications.
|
||||
|
||||
If you use saved plans (wisdom) or \courier{FFTW_ESTIMATE\} mode,
|
||||
however, then the algorithm is deterministic and the results should be
|
||||
identical between runs.
|
||||
|
||||
\question 26aug:savePlans Can I save FFTW's plans?
|
||||
|
||||
Yes. Starting with version 1.2, FFTW provides the \courier{wisdom\}
|
||||
mechanism for saving plans; see the FFTW manual.
|
||||
|
||||
\question 14sep:whyscaled Why does your inverse transform return a scaled result?
|
||||
|
||||
Computing the forward transform followed by the backward transform (or
|
||||
vice versa) yields the original array scaled by the size of the array.
|
||||
(For multi-dimensional transforms, the size of the array is the
|
||||
product of the dimensions.) We could, instead, have chosen a
|
||||
normalization that would have returned the unscaled array. Or, to
|
||||
accomodate the many conventions in this matter, the transform routines
|
||||
could have accepted a "scale factor" parameter. We did not do this,
|
||||
however, for two reasons. First, we didn't want to sacrifice
|
||||
performance in the common case where the scale factor is 1. Second, in
|
||||
real applications the FFT is followed or preceded by some computation
|
||||
on the data, into which the scale factor can typically be absorbed at
|
||||
little or no cost.
|
||||
|
||||
\question 02dec:centerorigin How can I make FFTW put the origin (zero frequency) at the center of its output?
|
||||
|
||||
For human viewing of a spectrum, it is often convenient to put the
|
||||
origin in frequency space at the center of the output array, rather
|
||||
than in the zero-th element (the default in FFTW). If all of the
|
||||
dimensions of your array are even, you can accomplish this by simply
|
||||
multiplying each element of the input array by (-1)^(i + j + ...),
|
||||
where i, j, etcetera are the indices of the element. (This trick is a
|
||||
general property of the DFT, and is not specific to FFTW.)
|
||||
|
||||
\question 08may:imageaudio How do I FFT an image/audio file in \italic{foobar\} format?
|
||||
|
||||
FFTW performs an FFT on an array of floating-point values. You can
|
||||
certainly use it to compute the transform of an image or audio stream,
|
||||
but you are responsible for figuring out your data format and
|
||||
converting it to the form FFTW requires.
|
||||
|
||||
\question 09apr:linkfails My program does not link (on Unix).
|
||||
|
||||
The libraries must be listed in the correct order (\courier{-lfftw3
|
||||
-lm\} for FFTW 3.x) and \italic{after\} your program sources/objects.
|
||||
(The general rule is that if \italic{A\} uses \italic{B\}, then
|
||||
\italic{A\} must be listed before \italic{B\} in the link command.).
|
||||
|
||||
\question 15mar:linkheader I included your header, but linking still fails.
|
||||
|
||||
You're a C++ programmer, aren't you? You have to compile the FFTW
|
||||
library and link it into your program, not just \courier{#include
|
||||
<fftw3.h>\}. (Yes, this is really a FAQ.)
|
||||
|
||||
\question 22oct:nostack My program crashes, complaining about stack space.
|
||||
|
||||
You cannot declare large arrays with automatic storage (e.g. via
|
||||
\courier{fftw_complex array[N]\}); you should use
|
||||
\courier{fftw_malloc\} (or equivalent) to allocate the arrays you want
|
||||
to transform if they are larger than a few hundred elements.
|
||||
|
||||
\question 13may:leaks FFTW seems to have a memory leak.
|
||||
|
||||
After you create a plan, FFTW caches the information required to
|
||||
quickly recreate the plan. (See \qref savePlans) It also maintains a
|
||||
small amount of other persistent memory. You can deallocate all of
|
||||
FFTW's internally allocated memory, if you wish, by calling
|
||||
\courier{fftw_cleanup()\}, as documented in the manual.
|
||||
|
||||
\question 16may:allzero The output of FFTW's transform is all zeros.
|
||||
|
||||
You should initialize your input array \italic{after\} creating the
|
||||
plan, unless you use \courier{FFTW_ESTIMATE\}: planning with
|
||||
\courier{FFTW_MEASURE\} or \courier{FFTW_PATIENT\} overwrites the
|
||||
input/output arrays, as described in the manual.
|
||||
|
||||
\question 05sep:vbetalia How do I call FFTW from the Microsoft language du jour?
|
||||
|
||||
Please \italic{do not\} ask us Windows-specific questions. We do not
|
||||
use Windows. We know nothing about Visual Basic, Visual C++, or .NET.
|
||||
Please find the appropriate Usenet discussion group and ask your
|
||||
question there. See also \qref runOnWindows.
|
||||
|
||||
\question 15oct:pruned Can I compute only a subset of the DFT outputs?
|
||||
|
||||
In general, no, an FFT intrinsically computes all outputs from all
|
||||
inputs. In principle, there is something called a \italic{pruned
|
||||
FFT\} that can do what you want, but to compute K outputs out of N the
|
||||
complexity is in general O(N log K) instead of O(N log N), thus saving
|
||||
only a small additive factor in the log. (The same argument holds if
|
||||
you instead have only K nonzero inputs.)
|
||||
|
||||
There are some specific cases in which you can get the O(N log K)
|
||||
performance benefits easily, however, by combining a few ordinary
|
||||
FFTs. In particular, the case where you want the first K outputs,
|
||||
where K divides N, can be handled by performing N/K transforms of size
|
||||
K and then summing the outputs multiplied by appropriate phase
|
||||
factors. For more details, see \docref{pruned FFTs with FFTW\}.
|
||||
|
||||
There are also some algorithms that compute pruned transforms
|
||||
\italic{approximately\}, but they are beyond the scope of this FAQ.
|
||||
|
||||
\question 21jan:transpose Can I use FFTW's routines for in-place and out-of-place matrix transposition?
|
||||
|
||||
You can use the FFTW guru interface to create a rank-0 transform of
|
||||
vector rank 2 where the vector strides are transposed. (A rank-0
|
||||
transform is equivalent to a 1D transform of size 1, which. just
|
||||
copies the input into the output.) Specifying the same location for
|
||||
the input and output makes the transpose in-place.
|
||||
|
||||
For double-valued data stored in row-major format, plan creation looks like
|
||||
this:
|
||||
|
||||
\verbatim
|
||||
fftw_plan plan_transpose(int rows, int cols, double *in, double *out)
|
||||
{
|
||||
const unsigned flags = FFTW_ESTIMATE; /* other flags are possible */
|
||||
fftw_iodim howmany_dims[2];
|
||||
|
||||
howmany_dims[0].n = rows;
|
||||
howmany_dims[0].is = cols;
|
||||
howmany_dims[0].os = 1;
|
||||
|
||||
howmany_dims[1].n = cols;
|
||||
howmany_dims[1].is = 1;
|
||||
howmany_dims[1].os = rows;
|
||||
|
||||
return fftw_plan_guru_r2r(/*rank=*/ 0, /*dims=*/ NULL,
|
||||
/*howmany_rank=*/ 2, howmany_dims,
|
||||
in, out, /*kind=*/ NULL, flags);
|
||||
}
|
||||
\endverbatim
|
||||
|
||||
(This entry was written by Rhys Ulerich.)
|
||||
|
||||
\comment ######################################################################
|
||||
|
||||
\section Internals of FFTW
|
||||
|
||||
\question 26aug:howworks How does FFTW work?
|
||||
|
||||
The innovation (if it can be so called) in FFTW consists in having a
|
||||
variety of composable \italic{solvers\}, representing different FFT
|
||||
algorithms and implementation strategies, whose combination into a
|
||||
particular \italic{plan\} for a given size can be determined at
|
||||
runtime according to the characteristics of your machine/compiler.
|
||||
This peculiar software architecture allows FFTW to adapt itself to
|
||||
almost any machine.
|
||||
|
||||
For more details (albeit somewhat outdated), see the paper "FFTW: An
|
||||
Adaptive Software Architecture for the FFT", by M. Frigo and
|
||||
S. G. Johnson, \italic{Proc. ICASSP\} 3, 1381 (1998), also
|
||||
available at \docref{the FFTW web page\}.
|
||||
|
||||
\question 26aug:whyfast Why is FFTW so fast?
|
||||
|
||||
This is a complex question, and there is no simple answer. In fact,
|
||||
the authors do not fully know the answer, either. In addition to many
|
||||
small performance hacks throughout FFTW, there are three general
|
||||
reasons for FFTW's speed.
|
||||
|
||||
\call startlist
|
||||
\call item
|
||||
FFTW uses a variety of FFT algorithms and implementation styles
|
||||
that can be arbitrarily composed to adapt itself to
|
||||
a machine. See \qref howworks.
|
||||
\call item
|
||||
FFTW uses a code generator to produce highly-optimized
|
||||
routines for computing small transforms.
|
||||
\call item
|
||||
FFTW uses explicit divide-and-conquer to take advantage
|
||||
of the memory hierarchy.
|
||||
\call endlist
|
||||
|
||||
For more details (albeit somewhat outdated), see the paper "FFTW: An
|
||||
Adaptive Software Architecture for the FFT", by M. Frigo and
|
||||
S. G. Johnson, \italic{Proc. ICASSP\} 3, 1381 (1998),
|
||||
available along with other references at \docref{the FFTW web page\}.
|
||||
|
||||
\comment ######################################################################
|
||||
|
||||
\section Known bugs
|
||||
|
||||
\question 27aug:rfftwndbug FFTW 1.1 crashes in rfftwnd on Linux.
|
||||
|
||||
This bug was fixed in FFTW 1.2. There was a bug in \courier{rfftwnd\}
|
||||
causing an incorrect amount of memory to be allocated. The bug showed
|
||||
up in Linux with libc-5.3.12 (and nowhere else that we know of).
|
||||
|
||||
\question 15oct:fftwmpibug The MPI transforms in FFTW 1.2 give incorrect results/leak memory.
|
||||
|
||||
These bugs were corrected in FFTW 1.2.1. The MPI transforms (really,
|
||||
just the transpose routines) in FFTW 1.2 had bugs that could cause
|
||||
errors in some situations.
|
||||
|
||||
\question 05nov:testsingbug The test programs in FFTW 1.2.1 fail when I change FFTW to use single precision.
|
||||
|
||||
This bug was fixed in FFTW 1.3. (Older versions of FFTW did
|
||||
work in single precision, but the test programs didn't--the error
|
||||
tolerances in the tests were set for double precision.)
|
||||
|
||||
\question 24mar:teststoobig The test program in FFTW 1.2.1 fails for n > 46340.
|
||||
|
||||
This bug was fixed in FFTW 1.3. FFTW 1.2.1 produced the right answer,
|
||||
but the test program was wrong. For large n, n*n in the naive
|
||||
transform that we used for comparison overflows 32 bit integer
|
||||
precision, breaking the test.
|
||||
|
||||
\question 24aug:linuxthreads The threaded code fails on Linux Redhat 5.0
|
||||
|
||||
We had problems with glibc-2.0.5. The code should work with
|
||||
glibc-2.0.7.
|
||||
|
||||
\question 26sep:bigrfftwnd FFTW 2.0's rfftwnd fails for rank > 1 transforms with a final dimension >= 65536.
|
||||
|
||||
This bug was fixed in FFTW 2.0.1. (There was a 32-bit integer overflow due
|
||||
to a poorly-parenthesized expression.)
|
||||
|
||||
\question 26mar:primebug FFTW 2.0's complex transforms give the wrong results with prime factors 17 to 97.
|
||||
|
||||
There was a bug in the complex transforms that could cause incorrect
|
||||
results under (hopefully rare) circumstances for lengths with
|
||||
intermediate-size prime factors (17-97). This bug was fixed in FFTW
|
||||
2.1.1.
|
||||
|
||||
\question 05apr:mpichbug FFTW 2.1.1's MPI test programs crash with MPICH.
|
||||
|
||||
This bug was fixed in FFTW 2.1.2. The 2.1/2.1.1 MPI test programs crashed
|
||||
when using the MPICH implementation of MPI with the \courier{ch_p4\}
|
||||
device (TCP/IP); the transforms themselves worked fine.
|
||||
|
||||
\question 25may:aixthreadbug FFTW 2.1.2's multi-threaded transforms don't work on AIX.
|
||||
|
||||
This bug was fixed in FFTW 2.1.3. The multi-threaded transforms in
|
||||
previous versions didn't work with AIX's \courier{pthreads\}
|
||||
implementation, which idiosyncratically creates threads in detached
|
||||
(non-joinable) mode by default.
|
||||
|
||||
\question 27sep:bigprimebug FFTW 2.1.2's complex transforms give incorrect results for large prime sizes.
|
||||
|
||||
This bug was fixed in FFTW 2.1.3. FFTW's complex-transform algorithm
|
||||
for prime sizes (in versions 2.0 to 2.1.2) had an integer overflow
|
||||
problem that caused incorrect results for many primes greater than
|
||||
32768 (on 32-bit machines). (Sizes without large prime factors are
|
||||
not affected.)
|
||||
|
||||
\question 25may:solaristhreadbug FFTW 2.1.3's multi-threaded transforms don't give any speedup on Solaris.
|
||||
|
||||
This bug was fixed in FFTW 2.1.4. (By default, Solaris creates
|
||||
threads that do not parallelize over multiple processors, so one has
|
||||
to request the proper behavior specifically.)
|
||||
|
||||
\question 03may:aixflags FFTW 2.1.3 crashes on AIX.
|
||||
|
||||
The FFTW 2.1.3 \courier{configure\} script picked incorrect compiler
|
||||
flags for the \courier{xlc\} compiler on newer IBM processors. This
|
||||
is fixed in FFTW 2.1.4.
|
||||
|
||||
\comment Here it ends!
|
||||
|
||||
110
fftw-3.3.10/doc/FAQ/fftw-faq.html/index.html
Normal file
110
fftw-3.3.10/doc/FAQ/fftw-faq.html/index.html
Normal file
@@ -0,0 +1,110 @@
|
||||
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
|
||||
<html>
|
||||
<head><title>
|
||||
FFTW Frequently Asked Questions with Answers
|
||||
</title>
|
||||
<link rev="made" href="mailto:fftw@fftw.org">
|
||||
<link rel="Contents" href="index.html">
|
||||
<link rel="Start" href="index.html">
|
||||
<META name="description"
|
||||
content="Frequently asked questions and answers (FAQ) for FFTW.">
|
||||
<link rel="Bookmark" title="FFTW FAQ" href="index.html">
|
||||
<LINK rel="Bookmark" title="FFTW Home Page"
|
||||
href="http://www.fftw.org">
|
||||
<LINK rel="Bookmark" title="FFTW Manual"
|
||||
href="http://www.fftw.org/doc/">
|
||||
</head><body text="#000000" bgcolor="#FFFFFF"><h1>
|
||||
FFTW Frequently Asked Questions with Answers
|
||||
</h1>
|
||||
This is the list of Frequently Asked Questions about FFTW, a
|
||||
collection of fast C routines for computing the Discrete Fourier
|
||||
Transform in one or more dimensions.
|
||||
<h1>
|
||||
Index
|
||||
</h1>
|
||||
|
||||
<ul>
|
||||
<li><b><font size="+2"><a href="section1.html" rel=subdocument>Section 1. Introduction and General Information</a></font></b>
|
||||
<li><a href="section1.html#whatisfftw" rel=subdocument>Q1.1. What is FFTW?</a>
|
||||
<li><a href="section1.html#whereisfftw" rel=subdocument>Q1.2. How do I obtain FFTW?</a>
|
||||
<li><a href="section1.html#isfftwfree" rel=subdocument>Q1.3. Is FFTW free software?</a>
|
||||
<li><a href="section1.html#nonfree" rel=subdocument>Q1.4. What is this about non-free licenses?</a>
|
||||
<li><a href="section1.html#west" rel=subdocument>Q1.5. In the West? I thought MIT was in the East?</a>
|
||||
<br><br><li><b><font size="+2"><a href="section2.html" rel=subdocument>Section 2. Installing FFTW</a></font></b>
|
||||
<li><a href="section2.html#systems" rel=subdocument>Q2.1. Which systems does FFTW run on?</a>
|
||||
<li><a href="section2.html#runOnWindows" rel=subdocument>Q2.2. Does FFTW run on Windows?</a>
|
||||
<li><a href="section2.html#compilerCrashes" rel=subdocument>Q2.3. My compiler has trouble with FFTW.</a>
|
||||
<li><a href="section2.html#solarisSucks" rel=subdocument>Q2.4. FFTW does not compile on Solaris, complaining about
|
||||
<code>const</code>.</a>
|
||||
<li><a href="section2.html#3dnow" rel=subdocument>Q2.5. What's the difference between <code>--enable-3dnow</code> and <code>--enable-k7</code>?</a>
|
||||
<li><a href="section2.html#fma" rel=subdocument>Q2.6. What's the difference between the fma and the non-fma
|
||||
versions?</a>
|
||||
<li><a href="section2.html#languages" rel=subdocument>Q2.7. Which language is FFTW written in?</a>
|
||||
<li><a href="section2.html#fortran" rel=subdocument>Q2.8. Can I call FFTW from Fortran?</a>
|
||||
<li><a href="section2.html#cplusplus" rel=subdocument>Q2.9. Can I call FFTW from C++?</a>
|
||||
<li><a href="section2.html#whynotfortran" rel=subdocument>Q2.10. Why isn't FFTW written in Fortran/C++?</a>
|
||||
<li><a href="section2.html#singleprec" rel=subdocument>Q2.11. How do I compile FFTW to run in single precision?</a>
|
||||
<li><a href="section2.html#64bitk7" rel=subdocument>Q2.12. --enable-k7 does not work on x86-64</a>
|
||||
<br><br><li><b><font size="+2"><a href="section3.html" rel=subdocument>Section 3. Using FFTW</a></font></b>
|
||||
<li><a href="section3.html#fftw2to3" rel=subdocument>Q3.1. Why not support the FFTW 2 interface in FFTW
|
||||
3?</a>
|
||||
<li><a href="section3.html#planperarray" rel=subdocument>Q3.2. Why do FFTW 3 plans encapsulate the input/output arrays and not just
|
||||
the algorithm?</a>
|
||||
<li><a href="section3.html#slow" rel=subdocument>Q3.3. FFTW seems really slow.</a>
|
||||
<li><a href="section3.html#slows" rel=subdocument>Q3.4. FFTW slows down after repeated calls.</a>
|
||||
<li><a href="section3.html#segfault" rel=subdocument>Q3.5. An FFTW routine is crashing when I call it.</a>
|
||||
<li><a href="section3.html#fortran64" rel=subdocument>Q3.6. My Fortran program crashes when calling FFTW.</a>
|
||||
<li><a href="section3.html#conventions" rel=subdocument>Q3.7. FFTW gives results different from my old
|
||||
FFT.</a>
|
||||
<li><a href="section3.html#nondeterministic" rel=subdocument>Q3.8. FFTW gives different results between runs</a>
|
||||
<li><a href="section3.html#savePlans" rel=subdocument>Q3.9. Can I save FFTW's plans?</a>
|
||||
<li><a href="section3.html#whyscaled" rel=subdocument>Q3.10. Why does your inverse transform return a scaled
|
||||
result?</a>
|
||||
<li><a href="section3.html#centerorigin" rel=subdocument>Q3.11. How can I make FFTW put the origin (zero frequency) at the center of
|
||||
its output?</a>
|
||||
<li><a href="section3.html#imageaudio" rel=subdocument>Q3.12. How do I FFT an image/audio file in <i>foobar</i> format?</a>
|
||||
<li><a href="section3.html#linkfails" rel=subdocument>Q3.13. My program does not link (on Unix).</a>
|
||||
<li><a href="section3.html#linkheader" rel=subdocument>Q3.14. I included your header, but linking still
|
||||
fails.</a>
|
||||
<li><a href="section3.html#nostack" rel=subdocument>Q3.15. My program crashes, complaining about stack
|
||||
space.</a>
|
||||
<li><a href="section3.html#leaks" rel=subdocument>Q3.16. FFTW seems to have a memory leak.</a>
|
||||
<li><a href="section3.html#allzero" rel=subdocument>Q3.17. The output of FFTW's transform is all zeros.</a>
|
||||
<li><a href="section3.html#vbetalia" rel=subdocument>Q3.18. How do I call FFTW from the Microsoft language du
|
||||
jour?</a>
|
||||
<li><a href="section3.html#pruned" rel=subdocument>Q3.19. Can I compute only a subset of the DFT outputs?</a>
|
||||
<li><a href="section3.html#transpose" rel=subdocument>Q3.20. Can I use FFTW's routines for in-place and out-of-place matrix
|
||||
transposition?</a>
|
||||
<br><br><li><b><font size="+2"><a href="section4.html" rel=subdocument>Section 4. Internals of FFTW</a></font></b>
|
||||
<li><a href="section4.html#howworks" rel=subdocument>Q4.1. How does FFTW work?</a>
|
||||
<li><a href="section4.html#whyfast" rel=subdocument>Q4.2. Why is FFTW so fast?</a>
|
||||
<br><br><li><b><font size="+2"><a href="section5.html" rel=subdocument>Section 5. Known bugs</a></font></b>
|
||||
<li><a href="section5.html#rfftwndbug" rel=subdocument>Q5.1. FFTW 1.1 crashes in rfftwnd on Linux.</a>
|
||||
<li><a href="section5.html#fftwmpibug" rel=subdocument>Q5.2. The MPI transforms in FFTW 1.2 give incorrect results/leak
|
||||
memory.</a>
|
||||
<li><a href="section5.html#testsingbug" rel=subdocument>Q5.3. The test programs in FFTW 1.2.1 fail when I change FFTW to use single
|
||||
precision.</a>
|
||||
<li><a href="section5.html#teststoobig" rel=subdocument>Q5.4. The test program in FFTW 1.2.1 fails for n >
|
||||
46340.</a>
|
||||
<li><a href="section5.html#linuxthreads" rel=subdocument>Q5.5. The threaded code fails on Linux Redhat 5.0</a>
|
||||
<li><a href="section5.html#bigrfftwnd" rel=subdocument>Q5.6. FFTW 2.0's rfftwnd fails for rank > 1 transforms with a final
|
||||
dimension >= 65536.</a>
|
||||
<li><a href="section5.html#primebug" rel=subdocument>Q5.7. FFTW 2.0's complex transforms give the wrong results with prime
|
||||
factors 17 to 97.</a>
|
||||
<li><a href="section5.html#mpichbug" rel=subdocument>Q5.8. FFTW 2.1.1's MPI test programs crash with
|
||||
MPICH.</a>
|
||||
<li><a href="section5.html#aixthreadbug" rel=subdocument>Q5.9. FFTW 2.1.2's multi-threaded transforms don't work on
|
||||
AIX.</a>
|
||||
<li><a href="section5.html#bigprimebug" rel=subdocument>Q5.10. FFTW 2.1.2's complex transforms give incorrect results for large prime
|
||||
sizes.</a>
|
||||
<li><a href="section5.html#solaristhreadbug" rel=subdocument>Q5.11. FFTW 2.1.3's multi-threaded transforms don't give any speedup on
|
||||
Solaris.</a>
|
||||
<li><a href="section5.html#aixflags" rel=subdocument>Q5.12. FFTW 2.1.3 crashes on AIX.</a>
|
||||
</ul><hr>
|
||||
<address>
|
||||
<A href="http://www.fftw.org">Matteo Frigo and Steven G. Johnson</A> / <A href="mailto:fftw@fftw.org">fftw@fftw.org</A>
|
||||
- 14 September 2021
|
||||
</address><br>
|
||||
Extracted from FFTW Frequently Asked Questions with Answers,
|
||||
Copyright © 2021 Matteo Frigo and Massachusetts Institute of Technology.
|
||||
</body></html>
|
||||
85
fftw-3.3.10/doc/FAQ/fftw-faq.html/section1.html
Normal file
85
fftw-3.3.10/doc/FAQ/fftw-faq.html/section1.html
Normal file
@@ -0,0 +1,85 @@
|
||||
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
|
||||
<html>
|
||||
<head><title>
|
||||
FFTW FAQ - Section 1
|
||||
</title>
|
||||
<link rev="made" href="mailto:fftw@fftw.org">
|
||||
<link rel="Contents" href="index.html">
|
||||
<link rel="Start" href="index.html">
|
||||
<link rel="Next" href="section2.html"><link rel="Bookmark" title="FFTW FAQ" href="index.html">
|
||||
</head><body text="#000000" bgcolor="#FFFFFF"><h1>
|
||||
FFTW FAQ - Section 1 <br>
|
||||
Introduction and General Information
|
||||
</h1>
|
||||
|
||||
<ul>
|
||||
<li><a href="#whatisfftw" rel=subdocument>Q1.1. What is FFTW?</a>
|
||||
<li><a href="#whereisfftw" rel=subdocument>Q1.2. How do I obtain FFTW?</a>
|
||||
<li><a href="#isfftwfree" rel=subdocument>Q1.3. Is FFTW free software?</a>
|
||||
<li><a href="#nonfree" rel=subdocument>Q1.4. What is this about non-free licenses?</a>
|
||||
<li><a href="#west" rel=subdocument>Q1.5. In the West? I thought MIT was in the East?</a>
|
||||
</ul><hr>
|
||||
|
||||
<h2><A name="whatisfftw">
|
||||
Question 1.1. What is FFTW?
|
||||
</A></h2>
|
||||
|
||||
FFTW is a free collection of fast C routines for computing the
|
||||
Discrete Fourier Transform in one or more dimensions. It includes
|
||||
complex, real, symmetric, and parallel transforms, and can handle
|
||||
arbitrary array sizes efficiently. FFTW is typically faster than
|
||||
other publically-available FFT implementations, and is even
|
||||
competitive with vendor-tuned libraries. (See our web page for
|
||||
extensive benchmarks.) To achieve this performance, FFTW uses novel
|
||||
code-generation and runtime self-optimization techniques (along with
|
||||
many other tricks).
|
||||
<h2><A name="whereisfftw">
|
||||
Question 1.2. How do I obtain FFTW?
|
||||
</A></h2>
|
||||
|
||||
FFTW can be found at <A href="http://www.fftw.org">the FFTW web page</A>. You can also retrieve it from <code>ftp.fftw.org</code> in <A href="ftp://ftp.fftw.org/pub/fftw"><code>/pub/fftw</code></A>.
|
||||
<h2><A name="isfftwfree">
|
||||
Question 1.3. Is FFTW free software?
|
||||
</A></h2>
|
||||
|
||||
Starting with version 1.3, FFTW is Free Software in the technical
|
||||
sense defined by the Free Software Foundation (see
|
||||
<A href="http://www.gnu.org/philosophy/categories.html">Categories of Free and Non-Free Software</A>), and is distributed under the terms of the GNU General Public License. Previous versions of FFTW were
|
||||
distributed without fee for noncommercial use, but were not
|
||||
technically ``free.''
|
||||
<p>
|
||||
Non-free licenses for FFTW are also available that permit different
|
||||
terms of use than the GPL.
|
||||
<h2><A name="nonfree">
|
||||
Question 1.4. What is this about non-free
|
||||
licenses?
|
||||
</A></h2>
|
||||
|
||||
The non-free licenses are for companies that wish to use FFTW in their
|
||||
products but are unwilling to release their software under the GPL
|
||||
(which would require them to release source code and allow free
|
||||
redistribution). Such users can purchase an unlimited-use license
|
||||
from MIT. Contact us for more details.
|
||||
|
||||
<p>
|
||||
We could instead have released FFTW under the LGPL, or even disallowed
|
||||
non-Free usage. Suffice it to say, however, that MIT owns the
|
||||
copyright to FFTW and they only let us GPL it because we convinced
|
||||
them that it would neither affect their licensing revenue nor irritate
|
||||
existing licensees.
|
||||
<h2><A name="west">
|
||||
Question 1.5. In the West? I thought MIT was in the
|
||||
East?
|
||||
</A></h2>
|
||||
|
||||
Not to an Italian. You could say that we're a Spaghetti Western
|
||||
(with apologies to Sergio Leone). <hr>
|
||||
Next: <a href="section2.html" rel=precedes>Installing FFTW</a>.<br>
|
||||
<a href="index.html" rev=subdocument>Return to contents</a>.<p>
|
||||
<address>
|
||||
<A href="http://www.fftw.org">Matteo Frigo and Steven G. Johnson</A> / <A href="mailto:fftw@fftw.org">fftw@fftw.org</A>
|
||||
- 14 September 2021
|
||||
</address><br>
|
||||
Extracted from FFTW Frequently Asked Questions with Answers,
|
||||
Copyright © 2021 Matteo Frigo and Massachusetts Institute of Technology.
|
||||
</body></html>
|
||||
285
fftw-3.3.10/doc/FAQ/fftw-faq.html/section2.html
Normal file
285
fftw-3.3.10/doc/FAQ/fftw-faq.html/section2.html
Normal file
@@ -0,0 +1,285 @@
|
||||
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
|
||||
<html>
|
||||
<head><title>
|
||||
FFTW FAQ - Section 2
|
||||
</title>
|
||||
<link rev="made" href="mailto:fftw@fftw.org">
|
||||
<link rel="Contents" href="index.html">
|
||||
<link rel="Start" href="index.html">
|
||||
<link rel="Next" href="section3.html"><link rel="Previous" href="section1.html"><link rel="Bookmark" title="FFTW FAQ" href="index.html">
|
||||
</head><body text="#000000" bgcolor="#FFFFFF"><h1>
|
||||
FFTW FAQ - Section 2 <br>
|
||||
Installing FFTW
|
||||
</h1>
|
||||
|
||||
<ul>
|
||||
<li><a href="#systems" rel=subdocument>Q2.1. Which systems does FFTW run on?</a>
|
||||
<li><a href="#runOnWindows" rel=subdocument>Q2.2. Does FFTW run on Windows?</a>
|
||||
<li><a href="#compilerCrashes" rel=subdocument>Q2.3. My compiler has trouble with FFTW.</a>
|
||||
<li><a href="#solarisSucks" rel=subdocument>Q2.4. FFTW does not compile on Solaris, complaining about
|
||||
<code>const</code>.</a>
|
||||
<li><a href="#3dnow" rel=subdocument>Q2.5. What's the difference between <code>--enable-3dnow</code> and <code>--enable-k7</code>?</a>
|
||||
<li><a href="#fma" rel=subdocument>Q2.6. What's the difference between the fma and the non-fma
|
||||
versions?</a>
|
||||
<li><a href="#languages" rel=subdocument>Q2.7. Which language is FFTW written in?</a>
|
||||
<li><a href="#fortran" rel=subdocument>Q2.8. Can I call FFTW from Fortran?</a>
|
||||
<li><a href="#cplusplus" rel=subdocument>Q2.9. Can I call FFTW from C++?</a>
|
||||
<li><a href="#whynotfortran" rel=subdocument>Q2.10. Why isn't FFTW written in Fortran/C++?</a>
|
||||
<li><a href="#singleprec" rel=subdocument>Q2.11. How do I compile FFTW to run in single precision?</a>
|
||||
<li><a href="#64bitk7" rel=subdocument>Q2.12. --enable-k7 does not work on x86-64</a>
|
||||
</ul><hr>
|
||||
|
||||
<h2><A name="systems">
|
||||
Question 2.1. Which systems does FFTW run
|
||||
on?
|
||||
</A></h2>
|
||||
|
||||
FFTW is written in ANSI C, and should work on any system with a decent
|
||||
C compiler. (See also <A href="#runOnWindows">Q2.2 `Does FFTW run on Windows?'</A>, <A href="#compilerCrashes">Q2.3 `My compiler has trouble with FFTW.'</A>.) FFTW can also take advantage of certain hardware-specific features,
|
||||
such as cycle counters and SIMD instructions, but this is optional.
|
||||
|
||||
<h2><A name="runOnWindows">
|
||||
Question 2.2. Does FFTW run on Windows?
|
||||
</A></h2>
|
||||
|
||||
Yes, many people have reported successfully using FFTW on Windows with
|
||||
various compilers. FFTW was not developed on Windows, but the source
|
||||
code is essentially straight ANSI C. See also the
|
||||
<A href="http://www.fftw.org/install/windows.html">FFTW Windows installation notes</A>, <A href="#compilerCrashes">Q2.3 `My compiler has trouble with FFTW.'</A>, and <A href="section3.html#vbetalia">Q3.18 `How do I call FFTW from the Microsoft language du
|
||||
jour?'</A>.
|
||||
<h2><A name="compilerCrashes">
|
||||
Question 2.3. My compiler has trouble with
|
||||
FFTW.
|
||||
</A></h2>
|
||||
|
||||
Complain fiercely to the vendor of the compiler.
|
||||
|
||||
<p>
|
||||
We have successfully used <code>gcc</code> 3.2.x on x86 and PPC, a recent Compaq C compiler for Alpha, version 6 of IBM's
|
||||
<code>xlc</code> compiler for AIX, Intel's <code>icc</code> versions 5-7, and Sun WorkShop <code>cc</code> version 6.
|
||||
<p>
|
||||
FFTW is likely to push compilers to their limits, however, and several
|
||||
compiler bugs have been exposed by FFTW. A partial list follows.
|
||||
|
||||
<p>
|
||||
<code>gcc</code> 2.95.x for Solaris/SPARC produces incorrect code for
|
||||
the test program (workaround: recompile the
|
||||
<code>libbench2</code> directory with <code>-O2</code>).
|
||||
<p>
|
||||
NetBSD/macppc 1.6 comes with a <code>gcc</code> version that also miscompiles the test program. (Please report a workaround if you know
|
||||
one.)
|
||||
<p>
|
||||
<code>gcc</code> 3.2.3 for ARM reportedly crashes during compilation.
|
||||
This bug is reportedly fixed in later versions of
|
||||
<code>gcc</code>.
|
||||
<p>
|
||||
Versions 8.0 and 8.1 of Intel's <code>icc</code> falsely claim to be <code>gcc</code>, so you should specify <code>CC="icc -no-gcc"</code>; this is automatic in FFTW 3.1. <code>icc-8.0.066</code> reportely produces incorrect code for FFTW 2.1.5, but is fixed in version 8.1.
|
||||
<code>icc-7.1</code> compiler build 20030402Z appears to produce
|
||||
incorrect dependencies, causing the compilation to fail.
|
||||
<code>icc-7.1</code> build 20030307Z appears to work fine. (Use
|
||||
<code>icc -V</code> to check which build you have.) As of 2003/04/18,
|
||||
build 20030402Z appears not to be available any longer on Intel's
|
||||
website, whereas the older build 20030307Z is available.
|
||||
|
||||
<p>
|
||||
<code>ranlib</code> of GNU <code>binutils</code> 2.9.1 on Irix has been observed to corrupt the FFTW libraries, causing a link failure when
|
||||
FFTW is compiled. Since <code>ranlib</code> is completely superfluous on Irix, we suggest deleting it from your system and replacing it with
|
||||
a symbolic link to <code>/bin/echo</code>.
|
||||
<p>
|
||||
If support for SIMD instructions is enabled in FFTW, further compiler
|
||||
problems may appear:
|
||||
<p>
|
||||
<code>gcc</code> 3.4.[0123] for x86 produces incorrect SSE2 code for
|
||||
FFTW when <code>-O2</code> (the best choice for FFTW) is used, causing
|
||||
FFTW to crash (<code>make check</code> crashes). This bug is fixed in <code>gcc</code> 3.4.4. On x86_64 (amd64/em64t), <code>gcc</code> 3.4.4 reportedly still has a similar problem, but this is fixed as of
|
||||
<code>gcc</code> 3.4.6.
|
||||
<p>
|
||||
<code>gcc-3.2</code> for x86 produces incorrect SIMD code if
|
||||
<code>-O3</code> is used. The same compiler produces incorrect SIMD
|
||||
code if no optimization is used, too. When using
|
||||
<code>gcc-3.2</code>, it is a good idea not to change the default
|
||||
<code>CFLAGS</code> selected by the <code>configure</code> script.
|
||||
<p>
|
||||
Some 3.0.x and 3.1.x versions of <code>gcc</code> on <code>x86</code> may crash. <code>gcc</code> so-called 2.96 shipping with RedHat 7.3 crashes
|
||||
when compiling SIMD code. In both cases, please upgrade to
|
||||
<code>gcc-3.2</code> or later.
|
||||
<p>
|
||||
Intel's <code>icc</code> 6.0 misaligns SSE constants, but FFTW has a
|
||||
workaround. <code>icc</code> 8.x fails to compile FFTW 3.0.x because it
|
||||
falsely claims to be <code>gcc</code>; we believe this to be a bug in <code>icc</code>, but FFTW 3.1 has a workaround.
|
||||
<p>
|
||||
Visual C++ 2003 reportedly produces incorrect code for SSE/SSE2 when
|
||||
compiling FFTW. This bug was reportedly fixed in VC++ 2005;
|
||||
alternatively, you could switch to the Intel compiler. VC++ 6.0 also
|
||||
reportedly produces incorrect code for the file
|
||||
<code>reodft11e-r2hc-odd.c</code> unless optimizations are disabled for that file.
|
||||
<p>
|
||||
<code>gcc</code> 2.95 on MacOS X miscompiles AltiVec code (fixed in
|
||||
later versions). <code>gcc</code> 3.2.x miscompiles AltiVec permutations, but FFTW has a workaround.
|
||||
<code>gcc</code> 4.0.1 on MacOS for Intel crashes when compiling FFTW; a workaround is to
|
||||
compile one file without optimization: <code>cd kernel; make CFLAGS=" " trig.lo</code>.
|
||||
<p>
|
||||
<code>gcc</code> 4.1.1 reportedly crashes when compiling FFTW for MIPS;
|
||||
the workaround is to compile the file it crashes on
|
||||
(<code>t2_64.c</code>) with a lower optimization level.
|
||||
<p>
|
||||
<code>gcc</code> versions 4.1.2 to 4.2.0 for x86 reportedly miscompile
|
||||
FFTW 3.1's test program, causing <code>make check</code> to crash (<code>gcc</code> bug #26528). The bug was reportedly fixed in
|
||||
<code>gcc</code> version 4.2.1 and later. A workaround is to compile
|
||||
<code>libbench2/verify-lib.c</code> without optimization.
|
||||
<h2><A name="solarisSucks">
|
||||
Question 2.4. FFTW does not compile on Solaris, complaining about
|
||||
<code>const</code>.
|
||||
</A></h2>
|
||||
|
||||
We know that at least on Solaris 2.5.x with Sun's compilers 4.2 you
|
||||
might get error messages from <code>make</code> such as
|
||||
<p>
|
||||
<code>"./fftw.h", line 88: warning: const is a keyword in ANSI
|
||||
C</code>
|
||||
<p>
|
||||
This is the case when the <code>configure</code> script reports that <code>const</code> does not work:
|
||||
<p>
|
||||
<code>checking for working const... (cached) no</code>
|
||||
<p>
|
||||
You should be aware that Solaris comes with two compilers, namely,
|
||||
<code>/opt/SUNWspro/SC4.2/bin/cc</code> and <code>/usr/ucb/cc</code>. The latter compiler is non-ANSI. Indeed, it is a perverse shell script
|
||||
that calls the real compiler in non-ANSI mode. In order
|
||||
to compile FFTW, change your path so that the right
|
||||
<code>cc</code> is used.
|
||||
<p>
|
||||
To know whether your compiler is the right one, type
|
||||
<code>cc -V</code>. If the compiler prints ``<code>ucbcc</code>'', as in
|
||||
<p>
|
||||
<code>ucbcc: WorkShop Compilers 4.2 30 Oct 1996 C
|
||||
4.2</code>
|
||||
<p>
|
||||
then the compiler is wrong. The right message is something like
|
||||
|
||||
<p>
|
||||
<code>cc: WorkShop Compilers 4.2 30 Oct 1996 C
|
||||
4.2</code>
|
||||
<h2><A name="3dnow">
|
||||
Question 2.5. What's the difference between
|
||||
<code>--enable-3dnow</code> and <code>--enable-k7</code>?
|
||||
</A></h2>
|
||||
|
||||
<code>--enable-k7</code> enables 3DNow! instructions on K7 processors
|
||||
(AMD Athlon and its variants). K7 support is provided by assembly
|
||||
routines generated by a special purpose compiler.
|
||||
As of fftw-3.2, --enable-k7 is no longer supported.
|
||||
|
||||
<p>
|
||||
<code>--enable-3dnow</code> enables generic 3DNow! support using <code>gcc</code> builtin functions. This works on earlier AMD
|
||||
processors, but it is not as fast as our special assembly routines.
|
||||
As of fftw-3.1, --enable-3dnow is no longer supported.
|
||||
|
||||
<h2><A name="fma">
|
||||
Question 2.6. What's the difference between the fma and the non-fma
|
||||
versions?
|
||||
</A></h2>
|
||||
|
||||
The fma version tries to exploit the fused multiply-add instructions
|
||||
implemented in many processors such as PowerPC, ia-64, and MIPS. The
|
||||
two FFTW packages are otherwise identical. In FFTW 3.1, the fma and
|
||||
non-fma versions were merged together into a single package, and the
|
||||
<code>configure</code> script attempts to automatically guess which
|
||||
version to use.
|
||||
<p>
|
||||
The FFTW 3.1 <code>configure</code> script enables fma by default on PowerPC, Itanium, and PA-RISC, and disables it otherwise. You can
|
||||
force one or the other by using the <code>--enable-fma</code> or <code>--disable-fma</code> flag for <code>configure</code>.
|
||||
<p>
|
||||
Definitely use fma if you have a PowerPC-based system with
|
||||
<code>gcc</code> (or IBM <code>xlc</code>). This includes all GNU/Linux systems for PowerPC and the older PowerPC-based MacOS systems. Also
|
||||
use it on PA-RISC and Itanium with the HP/UX compiler.
|
||||
|
||||
<p>
|
||||
Definitely do not use the fma version if you have an ia-32 processor
|
||||
(Intel, AMD, MacOS on Intel, etcetera).
|
||||
|
||||
<p>
|
||||
For other architectures/compilers, the situation is not so clear. For
|
||||
example, ia-64 has the fma instruction, but
|
||||
<code>gcc-3.2</code> appears not to exploit it correctly. Other compilers may do the right thing,
|
||||
but we have not tried them. Please send us your feedback so that we
|
||||
can update this FAQ entry.
|
||||
<h2><A name="languages">
|
||||
Question 2.7. Which language is FFTW written
|
||||
in?
|
||||
</A></h2>
|
||||
|
||||
FFTW is written in ANSI C. Most of the code, however, was
|
||||
automatically generated by a program called
|
||||
<code>genfft</code>, written in the Objective Caml dialect of ML. You do not need to know ML or to
|
||||
have an Objective Caml compiler in order to use FFTW.
|
||||
|
||||
<p>
|
||||
<code>genfft</code> is provided with the FFTW sources, which means that
|
||||
you can play with the code generator if you want. In this case, you
|
||||
need a working Objective Caml system. Objective Caml is available
|
||||
from <A href="http://caml.inria.fr">the Caml web page</A>.
|
||||
<h2><A name="fortran">
|
||||
Question 2.8. Can I call FFTW from Fortran?
|
||||
</A></h2>
|
||||
|
||||
Yes, FFTW (versions 1.3 and higher) contains a Fortran-callable
|
||||
interface, documented in the FFTW manual.
|
||||
|
||||
<p>
|
||||
By default, FFTW configures its Fortran interface to work with the
|
||||
first compiler it finds, e.g. <code>g77</code>. To configure for a different, incompatible Fortran compiler
|
||||
<code>foobar</code>, use <code>./configure F77=foobar</code> when installing FFTW. (In the case of <code>g77</code>, however, FFTW 3.x also includes an extra set of
|
||||
Fortran-callable routines with one less underscore at the end of
|
||||
identifiers, which should cover most other Fortran compilers on Linux
|
||||
at least.)
|
||||
<h2><A name="cplusplus">
|
||||
Question 2.9. Can I call FFTW from C++?
|
||||
</A></h2>
|
||||
|
||||
Most definitely. FFTW should compile and/or link under any C++
|
||||
compiler. Moreover, it is likely that the C++
|
||||
<code><complex></code> template class is bit-compatible with FFTW's complex-number format
|
||||
(see the FFTW manual for more details).
|
||||
|
||||
<h2><A name="whynotfortran">
|
||||
Question 2.10. Why isn't FFTW written in
|
||||
Fortran/C++?
|
||||
</A></h2>
|
||||
|
||||
Because we don't like those languages, and neither approaches the
|
||||
portability of C.
|
||||
<h2><A name="singleprec">
|
||||
Question 2.11. How do I compile FFTW to run in single
|
||||
precision?
|
||||
</A></h2>
|
||||
|
||||
On a Unix system: <code>configure --enable-float</code>. On a non-Unix system: edit <code>config.h</code> to <code>#define</code> the symbol <code>FFTW_SINGLE</code> (for FFTW 3.x). In both cases, you must then
|
||||
recompile FFTW. In FFTW 3, all FFTW identifiers will then begin with
|
||||
<code>fftwf_</code> instead of <code>fftw_</code>.
|
||||
<h2><A name="64bitk7">
|
||||
Question 2.12. --enable-k7 does not work on
|
||||
x86-64
|
||||
</A></h2>
|
||||
|
||||
Support for --enable-k7 was discontinued in fftw-3.2.
|
||||
|
||||
<p>
|
||||
The fftw-3.1 release supports --enable-k7. This option only works on
|
||||
32-bit x86 machines that implement 3DNow!, including the AMD Athlon
|
||||
and the AMD Opteron in 32-bit mode. --enable-k7 does not work on AMD
|
||||
Opteron in 64-bit mode. Use --enable-sse for x86-64 machines.
|
||||
|
||||
<p>
|
||||
FFTW supports 3DNow! by means of assembly code generated by a
|
||||
special-purpose compiler. It is hard to produce assembly code that
|
||||
works in both 32-bit and 64-bit mode. <hr>
|
||||
Next: <a href="section3.html" rel=precedes>Using FFTW</a>.<br>
|
||||
Back: <a href="section1.html" rev=precedes>Introduction and General Information</a>.<br>
|
||||
<a href="index.html" rev=subdocument>Return to contents</a>.<p>
|
||||
<address>
|
||||
<A href="http://www.fftw.org">Matteo Frigo and Steven G. Johnson</A> / <A href="mailto:fftw@fftw.org">fftw@fftw.org</A>
|
||||
- 14 September 2021
|
||||
</address><br>
|
||||
Extracted from FFTW Frequently Asked Questions with Answers,
|
||||
Copyright © 2021 Matteo Frigo and Massachusetts Institute of Technology.
|
||||
</body></html>
|
||||
334
fftw-3.3.10/doc/FAQ/fftw-faq.html/section3.html
Normal file
334
fftw-3.3.10/doc/FAQ/fftw-faq.html/section3.html
Normal file
@@ -0,0 +1,334 @@
|
||||
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
|
||||
<html>
|
||||
<head><title>
|
||||
FFTW FAQ - Section 3
|
||||
</title>
|
||||
<link rev="made" href="mailto:fftw@fftw.org">
|
||||
<link rel="Contents" href="index.html">
|
||||
<link rel="Start" href="index.html">
|
||||
<link rel="Next" href="section4.html"><link rel="Previous" href="section2.html"><link rel="Bookmark" title="FFTW FAQ" href="index.html">
|
||||
</head><body text="#000000" bgcolor="#FFFFFF"><h1>
|
||||
FFTW FAQ - Section 3 <br>
|
||||
Using FFTW
|
||||
</h1>
|
||||
|
||||
<ul>
|
||||
<li><a href="#fftw2to3" rel=subdocument>Q3.1. Why not support the FFTW 2 interface in FFTW
|
||||
3?</a>
|
||||
<li><a href="#planperarray" rel=subdocument>Q3.2. Why do FFTW 3 plans encapsulate the input/output arrays and not just
|
||||
the algorithm?</a>
|
||||
<li><a href="#slow" rel=subdocument>Q3.3. FFTW seems really slow.</a>
|
||||
<li><a href="#slows" rel=subdocument>Q3.4. FFTW slows down after repeated calls.</a>
|
||||
<li><a href="#segfault" rel=subdocument>Q3.5. An FFTW routine is crashing when I call it.</a>
|
||||
<li><a href="#fortran64" rel=subdocument>Q3.6. My Fortran program crashes when calling FFTW.</a>
|
||||
<li><a href="#conventions" rel=subdocument>Q3.7. FFTW gives results different from my old
|
||||
FFT.</a>
|
||||
<li><a href="#nondeterministic" rel=subdocument>Q3.8. FFTW gives different results between runs</a>
|
||||
<li><a href="#savePlans" rel=subdocument>Q3.9. Can I save FFTW's plans?</a>
|
||||
<li><a href="#whyscaled" rel=subdocument>Q3.10. Why does your inverse transform return a scaled
|
||||
result?</a>
|
||||
<li><a href="#centerorigin" rel=subdocument>Q3.11. How can I make FFTW put the origin (zero frequency) at the center of
|
||||
its output?</a>
|
||||
<li><a href="#imageaudio" rel=subdocument>Q3.12. How do I FFT an image/audio file in <i>foobar</i> format?</a>
|
||||
<li><a href="#linkfails" rel=subdocument>Q3.13. My program does not link (on Unix).</a>
|
||||
<li><a href="#linkheader" rel=subdocument>Q3.14. I included your header, but linking still
|
||||
fails.</a>
|
||||
<li><a href="#nostack" rel=subdocument>Q3.15. My program crashes, complaining about stack
|
||||
space.</a>
|
||||
<li><a href="#leaks" rel=subdocument>Q3.16. FFTW seems to have a memory leak.</a>
|
||||
<li><a href="#allzero" rel=subdocument>Q3.17. The output of FFTW's transform is all zeros.</a>
|
||||
<li><a href="#vbetalia" rel=subdocument>Q3.18. How do I call FFTW from the Microsoft language du
|
||||
jour?</a>
|
||||
<li><a href="#pruned" rel=subdocument>Q3.19. Can I compute only a subset of the DFT outputs?</a>
|
||||
<li><a href="#transpose" rel=subdocument>Q3.20. Can I use FFTW's routines for in-place and out-of-place matrix
|
||||
transposition?</a>
|
||||
</ul><hr>
|
||||
|
||||
<h2><A name="fftw2to3">
|
||||
Question 3.1. Why not support the FFTW 2 interface in FFTW
|
||||
3?
|
||||
</A></h2>
|
||||
|
||||
FFTW 3 has semantics incompatible with earlier versions: its plans can
|
||||
only be used for a given stride, multiplicity, and other
|
||||
characteristics of the input and output arrays; these stronger
|
||||
semantics are necessary for performance reasons. Thus, it is
|
||||
impossible to efficiently emulate the older interface (whose plans can
|
||||
be used for any transform of the same size). We believe that it
|
||||
should be possible to upgrade most programs without any difficulty,
|
||||
however.
|
||||
<h2><A name="planperarray">
|
||||
Question 3.2. Why do FFTW 3 plans encapsulate the input/output arrays
|
||||
and not just the algorithm?
|
||||
</A></h2>
|
||||
|
||||
There are several reasons:
|
||||
<ul>
|
||||
<li>It was important for performance reasons that the plan be specific to
|
||||
array characteristics like the stride (and alignment, for SIMD), and
|
||||
requiring that the user maintain these invariants is error prone.
|
||||
|
||||
<li>In most high-performance applications, as far as we can tell, you are
|
||||
usually transforming the same array over and over, so FFTW's semantics
|
||||
should not be a burden.
|
||||
<li>If you need to transform another array of the same size, creating a
|
||||
new plan once the first exists is a cheap operation.
|
||||
|
||||
<li>If you need to transform many arrays of the same size at once, you
|
||||
should really use the <code>plan_many</code> routines in FFTW's "advanced"
|
||||
interface.
|
||||
<li>If the abovementioned array characteristics are the same, you are
|
||||
willing to pay close attention to the documentation, and you really
|
||||
need to, we provide a "new-array execution" interface to
|
||||
apply a plan to a new array.
|
||||
</ul>
|
||||
|
||||
<h2><A name="slow">
|
||||
Question 3.3. FFTW seems really slow.
|
||||
</A></h2>
|
||||
|
||||
You are probably recreating the plan before every transform, rather
|
||||
than creating it once and reusing it for all transforms of the same
|
||||
size. FFTW is designed to be used in the following way:
|
||||
|
||||
<ul>
|
||||
<li>First, you create a plan. This will take several seconds.
|
||||
|
||||
<li>Then, you reuse the plan many times to perform FFTs. These are fast.
|
||||
|
||||
</ul>
|
||||
If you don't need to compute many transforms and the time for the
|
||||
planner is significant, you have two options. First, you can use the
|
||||
<code>FFTW_ESTIMATE</code> option in the planner, which uses heuristics
|
||||
instead of runtime measurements and produces a good plan in a short
|
||||
time. Second, you can use the wisdom feature to precompute the plan;
|
||||
see <A href="#savePlans">Q3.9 `Can I save FFTW's plans?'</A>
|
||||
<h2><A name="slows">
|
||||
Question 3.4. FFTW slows down after repeated
|
||||
calls.
|
||||
</A></h2>
|
||||
|
||||
Probably, NaNs or similar are creeping into your data, and the
|
||||
slowdown is due to the resulting floating-point exceptions. For
|
||||
example, be aware that repeatedly FFTing the same array is a diverging
|
||||
process (because FFTW computes the unnormalized transform).
|
||||
|
||||
<h2><A name="segfault">
|
||||
Question 3.5. An FFTW routine is crashing when I call
|
||||
it.
|
||||
</A></h2>
|
||||
|
||||
Did the FFTW test programs pass (<code>make check</code>, or <code>cd tests; make bigcheck</code> if you want to be paranoid)? If so, you almost
|
||||
certainly have a bug in your own code. For example, you could be
|
||||
passing invalid arguments (such as wrongly-sized arrays) to FFTW, or
|
||||
you could simply have memory corruption elsewhere in your program that
|
||||
causes random crashes later on. Please don't complain to us unless
|
||||
you can come up with a minimal self-contained program (preferably
|
||||
under 30 lines) that illustrates the problem.
|
||||
|
||||
<h2><A name="fortran64">
|
||||
Question 3.6. My Fortran program crashes when calling
|
||||
FFTW.
|
||||
</A></h2>
|
||||
|
||||
As described in the manual, on 64-bit machines you must store the
|
||||
plans in variables large enough to hold a pointer, for example
|
||||
<code>integer*8</code>. We recommend using <code>integer*8</code> on 32-bit machines as well, to simplify porting.
|
||||
|
||||
<h2><A name="conventions">
|
||||
Question 3.7. FFTW gives results different from my old
|
||||
FFT.
|
||||
</A></h2>
|
||||
|
||||
People follow many different conventions for the DFT, and you should
|
||||
be sure to know the ones that we use (described in the FFTW manual).
|
||||
In particular, you should be aware that the
|
||||
<code>FFTW_FORWARD</code>/<code>FFTW_BACKWARD</code> directions correspond to signs of -1/+1 in the exponent of the DFT definition.
|
||||
(<i>Numerical Recipes</i> uses the opposite convention.)
|
||||
<p>
|
||||
You should also know that we compute an unnormalized transform. In
|
||||
contrast, Matlab is an example of program that computes a normalized
|
||||
transform. See <A href="#whyscaled">Q3.10 `Why does your inverse transform return a scaled
|
||||
result?'</A>.
|
||||
<p>
|
||||
Finally, note that floating-point arithmetic is not exact, so
|
||||
different FFT algorithms will give slightly different results (on the
|
||||
order of the numerical accuracy; typically a fractional difference of
|
||||
1e-15 or so in double precision).
|
||||
<h2><A name="nondeterministic">
|
||||
Question 3.8. FFTW gives different results between
|
||||
runs
|
||||
</A></h2>
|
||||
|
||||
If you use <code>FFTW_MEASURE</code> or <code>FFTW_PATIENT</code> mode, then the algorithm FFTW employs is not deterministic: it depends on
|
||||
runtime performance measurements. This will cause the results to vary
|
||||
slightly from run to run. However, the differences should be slight,
|
||||
on the order of the floating-point precision, and therefore should
|
||||
have no practical impact on most applications.
|
||||
|
||||
<p>
|
||||
If you use saved plans (wisdom) or <code>FFTW_ESTIMATE</code> mode, however, then the algorithm is deterministic and the results should be
|
||||
identical between runs.
|
||||
<h2><A name="savePlans">
|
||||
Question 3.9. Can I save FFTW's plans?
|
||||
</A></h2>
|
||||
|
||||
Yes. Starting with version 1.2, FFTW provides the
|
||||
<code>wisdom</code> mechanism for saving plans; see the FFTW manual.
|
||||
|
||||
<h2><A name="whyscaled">
|
||||
Question 3.10. Why does your inverse transform return a scaled
|
||||
result?
|
||||
</A></h2>
|
||||
|
||||
Computing the forward transform followed by the backward transform (or
|
||||
vice versa) yields the original array scaled by the size of the array.
|
||||
(For multi-dimensional transforms, the size of the array is the
|
||||
product of the dimensions.) We could, instead, have chosen a
|
||||
normalization that would have returned the unscaled array. Or, to
|
||||
accomodate the many conventions in this matter, the transform routines
|
||||
could have accepted a "scale factor" parameter. We did not
|
||||
do this, however, for two reasons. First, we didn't want to sacrifice
|
||||
performance in the common case where the scale factor is 1. Second, in
|
||||
real applications the FFT is followed or preceded by some computation
|
||||
on the data, into which the scale factor can typically be absorbed at
|
||||
little or no cost.
|
||||
<h2><A name="centerorigin">
|
||||
Question 3.11. How can I make FFTW put the origin (zero frequency) at
|
||||
the center of its output?
|
||||
</A></h2>
|
||||
|
||||
For human viewing of a spectrum, it is often convenient to put the
|
||||
origin in frequency space at the center of the output array, rather
|
||||
than in the zero-th element (the default in FFTW). If all of the
|
||||
dimensions of your array are even, you can accomplish this by simply
|
||||
multiplying each element of the input array by (-1)^(i + j + ...),
|
||||
where i, j, etcetera are the indices of the element. (This trick is a
|
||||
general property of the DFT, and is not specific to FFTW.)
|
||||
|
||||
<h2><A name="imageaudio">
|
||||
Question 3.12. How do I FFT an image/audio file in
|
||||
<i>foobar</i> format?
|
||||
</A></h2>
|
||||
|
||||
FFTW performs an FFT on an array of floating-point values. You can
|
||||
certainly use it to compute the transform of an image or audio stream,
|
||||
but you are responsible for figuring out your data format and
|
||||
converting it to the form FFTW requires.
|
||||
|
||||
<h2><A name="linkfails">
|
||||
Question 3.13. My program does not link (on
|
||||
Unix).
|
||||
</A></h2>
|
||||
|
||||
The libraries must be listed in the correct order
|
||||
(<code>-lfftw3 -lm</code> for FFTW 3.x) and <i>after</i> your program sources/objects. (The general rule is that if <i>A</i> uses <i>B</i>, then <i>A</i> must be listed before <i>B</i> in the link command.).
|
||||
<h2><A name="linkheader">
|
||||
Question 3.14. I included your header, but linking still
|
||||
fails.
|
||||
</A></h2>
|
||||
|
||||
You're a C++ programmer, aren't you? You have to compile the FFTW
|
||||
library and link it into your program, not just
|
||||
<code>#include <fftw3.h></code>. (Yes, this is really a FAQ.)
|
||||
<h2><A name="nostack">
|
||||
Question 3.15. My program crashes, complaining about stack
|
||||
space.
|
||||
</A></h2>
|
||||
|
||||
You cannot declare large arrays with automatic storage (e.g. via
|
||||
<code>fftw_complex array[N]</code>); you should use <code>fftw_malloc</code> (or equivalent) to allocate the arrays you want
|
||||
to transform if they are larger than a few hundred elements.
|
||||
|
||||
<h2><A name="leaks">
|
||||
Question 3.16. FFTW seems to have a memory
|
||||
leak.
|
||||
</A></h2>
|
||||
|
||||
After you create a plan, FFTW caches the information required to
|
||||
quickly recreate the plan. (See <A href="#savePlans">Q3.9 `Can I save FFTW's plans?'</A>) It also maintains a small amount of other persistent memory. You can deallocate all of
|
||||
FFTW's internally allocated memory, if you wish, by calling
|
||||
<code>fftw_cleanup()</code>, as documented in the manual.
|
||||
<h2><A name="allzero">
|
||||
Question 3.17. The output of FFTW's transform is all
|
||||
zeros.
|
||||
</A></h2>
|
||||
|
||||
You should initialize your input array <i>after</i> creating the plan, unless you use <code>FFTW_ESTIMATE</code>: planning with <code>FFTW_MEASURE</code> or <code>FFTW_PATIENT</code> overwrites the input/output arrays, as described in the manual.
|
||||
|
||||
<h2><A name="vbetalia">
|
||||
Question 3.18. How do I call FFTW from the Microsoft language du
|
||||
jour?
|
||||
</A></h2>
|
||||
|
||||
Please <i>do not</i> ask us Windows-specific questions. We do not
|
||||
use Windows. We know nothing about Visual Basic, Visual C++, or .NET.
|
||||
Please find the appropriate Usenet discussion group and ask your
|
||||
question there. See also <A href="section2.html#runOnWindows">Q2.2 `Does FFTW run on Windows?'</A>.
|
||||
<h2><A name="pruned">
|
||||
Question 3.19. Can I compute only a subset of the DFT
|
||||
outputs?
|
||||
</A></h2>
|
||||
|
||||
In general, no, an FFT intrinsically computes all outputs from all
|
||||
inputs. In principle, there is something called a
|
||||
<i>pruned FFT</i> that can do what you want, but to compute K outputs out of N the
|
||||
complexity is in general O(N log K) instead of O(N log N), thus saving
|
||||
only a small additive factor in the log. (The same argument holds if
|
||||
you instead have only K nonzero inputs.)
|
||||
|
||||
<p>
|
||||
There are some specific cases in which you can get the O(N log K)
|
||||
performance benefits easily, however, by combining a few ordinary
|
||||
FFTs. In particular, the case where you want the first K outputs,
|
||||
where K divides N, can be handled by performing N/K transforms of size
|
||||
K and then summing the outputs multiplied by appropriate phase
|
||||
factors. For more details, see <A href="http://www.fftw.org/pruned.html">pruned FFTs with FFTW</A>.
|
||||
<p>
|
||||
There are also some algorithms that compute pruned transforms
|
||||
<i>approximately</i>, but they are beyond the scope of this FAQ.
|
||||
|
||||
<h2><A name="transpose">
|
||||
Question 3.20. Can I use FFTW's routines for in-place and
|
||||
out-of-place matrix transposition?
|
||||
</A></h2>
|
||||
|
||||
You can use the FFTW guru interface to create a rank-0 transform of
|
||||
vector rank 2 where the vector strides are transposed. (A rank-0
|
||||
transform is equivalent to a 1D transform of size 1, which. just
|
||||
copies the input into the output.) Specifying the same location for
|
||||
the input and output makes the transpose in-place.
|
||||
|
||||
<p>
|
||||
For double-valued data stored in row-major format, plan creation looks
|
||||
like this: <pre>
|
||||
fftw_plan plan_transpose(int rows, int cols, double *in, double *out)
|
||||
{
|
||||
const unsigned flags = FFTW_ESTIMATE; /* other flags are possible */
|
||||
fftw_iodim howmany_dims[2];
|
||||
|
||||
howmany_dims[0].n = rows;
|
||||
howmany_dims[0].is = cols;
|
||||
howmany_dims[0].os = 1;
|
||||
|
||||
howmany_dims[1].n = cols;
|
||||
howmany_dims[1].is = 1;
|
||||
howmany_dims[1].os = rows;
|
||||
|
||||
return fftw_plan_guru_r2r(/*rank=*/ 0, /*dims=*/ NULL,
|
||||
/*howmany_rank=*/ 2, howmany_dims,
|
||||
in, out, /*kind=*/ NULL, flags);
|
||||
}
|
||||
</pre>
|
||||
(This entry was written by Rhys Ulerich.)
|
||||
<hr>
|
||||
Next: <a href="section4.html" rel=precedes>Internals of FFTW</a>.<br>
|
||||
Back: <a href="section2.html" rev=precedes>Installing FFTW</a>.<br>
|
||||
<a href="index.html" rev=subdocument>Return to contents</a>.<p>
|
||||
<address>
|
||||
<A href="http://www.fftw.org">Matteo Frigo and Steven G. Johnson</A> / <A href="mailto:fftw@fftw.org">fftw@fftw.org</A>
|
||||
- 14 September 2021
|
||||
</address><br>
|
||||
Extracted from FFTW Frequently Asked Questions with Answers,
|
||||
Copyright © 2021 Matteo Frigo and Massachusetts Institute of Technology.
|
||||
</body></html>
|
||||
64
fftw-3.3.10/doc/FAQ/fftw-faq.html/section4.html
Normal file
64
fftw-3.3.10/doc/FAQ/fftw-faq.html/section4.html
Normal file
@@ -0,0 +1,64 @@
|
||||
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
|
||||
<html>
|
||||
<head><title>
|
||||
FFTW FAQ - Section 4
|
||||
</title>
|
||||
<link rev="made" href="mailto:fftw@fftw.org">
|
||||
<link rel="Contents" href="index.html">
|
||||
<link rel="Start" href="index.html">
|
||||
<link rel="Next" href="section5.html"><link rel="Previous" href="section3.html"><link rel="Bookmark" title="FFTW FAQ" href="index.html">
|
||||
</head><body text="#000000" bgcolor="#FFFFFF"><h1>
|
||||
FFTW FAQ - Section 4 <br>
|
||||
Internals of FFTW
|
||||
</h1>
|
||||
|
||||
<ul>
|
||||
<li><a href="#howworks" rel=subdocument>Q4.1. How does FFTW work?</a>
|
||||
<li><a href="#whyfast" rel=subdocument>Q4.2. Why is FFTW so fast?</a>
|
||||
</ul><hr>
|
||||
|
||||
<h2><A name="howworks">
|
||||
Question 4.1. How does FFTW work?
|
||||
</A></h2>
|
||||
|
||||
The innovation (if it can be so called) in FFTW consists in having a
|
||||
variety of composable <i>solvers</i>, representing different FFT algorithms and implementation strategies, whose combination into a
|
||||
particular <i>plan</i> for a given size can be determined at runtime according to the characteristics of your machine/compiler.
|
||||
This peculiar software architecture allows FFTW to adapt itself to
|
||||
almost any machine.
|
||||
<p>
|
||||
For more details (albeit somewhat outdated), see the paper "FFTW:
|
||||
An Adaptive Software Architecture for the FFT", by M. Frigo and
|
||||
S. G. Johnson, <i>Proc. ICASSP</i> 3, 1381 (1998), also available at <A href="http://www.fftw.org">the FFTW web page</A>.
|
||||
<h2><A name="whyfast">
|
||||
Question 4.2. Why is FFTW so fast?
|
||||
</A></h2>
|
||||
|
||||
This is a complex question, and there is no simple answer. In fact,
|
||||
the authors do not fully know the answer, either. In addition to many
|
||||
small performance hacks throughout FFTW, there are three general
|
||||
reasons for FFTW's speed.
|
||||
<ul>
|
||||
<li> FFTW uses a variety of FFT algorithms and implementation styles
|
||||
that can be arbitrarily composed to adapt itself to
|
||||
a machine. See <A href="#howworks">Q4.1 `How does FFTW work?'</A>.
|
||||
<li> FFTW uses a code generator to produce highly-optimized
|
||||
routines for computing small transforms.
|
||||
|
||||
<li> FFTW uses explicit divide-and-conquer to take advantage
|
||||
of the memory hierarchy.
|
||||
</ul>
|
||||
For more details (albeit somewhat outdated), see the paper "FFTW:
|
||||
An Adaptive Software Architecture for the FFT", by M. Frigo and
|
||||
S. G. Johnson, <i>Proc. ICASSP</i> 3, 1381 (1998), available along with other references at
|
||||
<A href="http://www.fftw.org">the FFTW web page</A>. <hr>
|
||||
Next: <a href="section5.html" rel=precedes>Known bugs</a>.<br>
|
||||
Back: <a href="section3.html" rev=precedes>Using FFTW</a>.<br>
|
||||
<a href="index.html" rev=subdocument>Return to contents</a>.<p>
|
||||
<address>
|
||||
<A href="http://www.fftw.org">Matteo Frigo and Steven G. Johnson</A> / <A href="mailto:fftw@fftw.org">fftw@fftw.org</A>
|
||||
- 14 September 2021
|
||||
</address><br>
|
||||
Extracted from FFTW Frequently Asked Questions with Answers,
|
||||
Copyright © 2021 Matteo Frigo and Massachusetts Institute of Technology.
|
||||
</body></html>
|
||||
148
fftw-3.3.10/doc/FAQ/fftw-faq.html/section5.html
Normal file
148
fftw-3.3.10/doc/FAQ/fftw-faq.html/section5.html
Normal file
@@ -0,0 +1,148 @@
|
||||
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
|
||||
<html>
|
||||
<head><title>
|
||||
FFTW FAQ - Section 5
|
||||
</title>
|
||||
<link rev="made" href="mailto:fftw@fftw.org">
|
||||
<link rel="Contents" href="index.html">
|
||||
<link rel="Start" href="index.html">
|
||||
<link rel="Previous" href="section4.html"><link rel="Bookmark" title="FFTW FAQ" href="index.html">
|
||||
</head><body text="#000000" bgcolor="#FFFFFF"><h1>
|
||||
FFTW FAQ - Section 5 <br>
|
||||
Known bugs
|
||||
</h1>
|
||||
|
||||
<ul>
|
||||
<li><a href="#rfftwndbug" rel=subdocument>Q5.1. FFTW 1.1 crashes in rfftwnd on Linux.</a>
|
||||
<li><a href="#fftwmpibug" rel=subdocument>Q5.2. The MPI transforms in FFTW 1.2 give incorrect results/leak
|
||||
memory.</a>
|
||||
<li><a href="#testsingbug" rel=subdocument>Q5.3. The test programs in FFTW 1.2.1 fail when I change FFTW to use single
|
||||
precision.</a>
|
||||
<li><a href="#teststoobig" rel=subdocument>Q5.4. The test program in FFTW 1.2.1 fails for n >
|
||||
46340.</a>
|
||||
<li><a href="#linuxthreads" rel=subdocument>Q5.5. The threaded code fails on Linux Redhat 5.0</a>
|
||||
<li><a href="#bigrfftwnd" rel=subdocument>Q5.6. FFTW 2.0's rfftwnd fails for rank > 1 transforms with a final
|
||||
dimension >= 65536.</a>
|
||||
<li><a href="#primebug" rel=subdocument>Q5.7. FFTW 2.0's complex transforms give the wrong results with prime
|
||||
factors 17 to 97.</a>
|
||||
<li><a href="#mpichbug" rel=subdocument>Q5.8. FFTW 2.1.1's MPI test programs crash with
|
||||
MPICH.</a>
|
||||
<li><a href="#aixthreadbug" rel=subdocument>Q5.9. FFTW 2.1.2's multi-threaded transforms don't work on
|
||||
AIX.</a>
|
||||
<li><a href="#bigprimebug" rel=subdocument>Q5.10. FFTW 2.1.2's complex transforms give incorrect results for large prime
|
||||
sizes.</a>
|
||||
<li><a href="#solaristhreadbug" rel=subdocument>Q5.11. FFTW 2.1.3's multi-threaded transforms don't give any speedup on
|
||||
Solaris.</a>
|
||||
<li><a href="#aixflags" rel=subdocument>Q5.12. FFTW 2.1.3 crashes on AIX.</a>
|
||||
</ul><hr>
|
||||
|
||||
<h2><A name="rfftwndbug">
|
||||
Question 5.1. FFTW 1.1 crashes in rfftwnd on
|
||||
Linux.
|
||||
</A></h2>
|
||||
|
||||
This bug was fixed in FFTW 1.2. There was a bug in
|
||||
<code>rfftwnd</code> causing an incorrect amount of memory to be allocated. The bug showed
|
||||
up in Linux with libc-5.3.12 (and nowhere else that we know of).
|
||||
|
||||
<h2><A name="fftwmpibug">
|
||||
Question 5.2. The MPI transforms in FFTW 1.2 give incorrect
|
||||
results/leak memory.
|
||||
</A></h2>
|
||||
|
||||
These bugs were corrected in FFTW 1.2.1. The MPI transforms (really,
|
||||
just the transpose routines) in FFTW 1.2 had bugs that could cause
|
||||
errors in some situations.
|
||||
<h2><A name="testsingbug">
|
||||
Question 5.3. The test programs in FFTW 1.2.1 fail when I change FFTW
|
||||
to use single precision.
|
||||
</A></h2>
|
||||
|
||||
This bug was fixed in FFTW 1.3. (Older versions of FFTW did
|
||||
work in single precision, but the test programs didn't--the error
|
||||
tolerances in the tests were set for double precision.)
|
||||
|
||||
<h2><A name="teststoobig">
|
||||
Question 5.4. The test program in FFTW 1.2.1 fails for n >
|
||||
46340.
|
||||
</A></h2>
|
||||
|
||||
This bug was fixed in FFTW 1.3. FFTW 1.2.1 produced the right answer,
|
||||
but the test program was wrong. For large n, n*n in the naive
|
||||
transform that we used for comparison overflows 32 bit integer
|
||||
precision, breaking the test.
|
||||
<h2><A name="linuxthreads">
|
||||
Question 5.5. The threaded code fails on Linux Redhat
|
||||
5.0
|
||||
</A></h2>
|
||||
|
||||
We had problems with glibc-2.0.5. The code should work with
|
||||
glibc-2.0.7.
|
||||
<h2><A name="bigrfftwnd">
|
||||
Question 5.6. FFTW 2.0's rfftwnd fails for rank > 1 transforms
|
||||
with a final dimension >= 65536.
|
||||
</A></h2>
|
||||
|
||||
This bug was fixed in FFTW 2.0.1. (There was a 32-bit integer
|
||||
overflow due to a poorly-parenthesized expression.)
|
||||
<h2><A name="primebug">
|
||||
Question 5.7. FFTW 2.0's complex transforms give the wrong results
|
||||
with prime factors 17 to 97.
|
||||
</A></h2>
|
||||
|
||||
There was a bug in the complex transforms that could cause incorrect
|
||||
results under (hopefully rare) circumstances for lengths with
|
||||
intermediate-size prime factors (17-97). This bug was fixed in FFTW
|
||||
2.1.1.
|
||||
<h2><A name="mpichbug">
|
||||
Question 5.8. FFTW 2.1.1's MPI test programs crash with
|
||||
MPICH.
|
||||
</A></h2>
|
||||
|
||||
This bug was fixed in FFTW 2.1.2. The 2.1/2.1.1 MPI test programs
|
||||
crashed when using the MPICH implementation of MPI with the
|
||||
<code>ch_p4</code> device (TCP/IP); the transforms themselves worked fine.
|
||||
|
||||
<h2><A name="aixthreadbug">
|
||||
Question 5.9. FFTW 2.1.2's multi-threaded transforms don't work on
|
||||
AIX.
|
||||
</A></h2>
|
||||
|
||||
This bug was fixed in FFTW 2.1.3. The multi-threaded transforms in
|
||||
previous versions didn't work with AIX's
|
||||
<code>pthreads</code> implementation, which idiosyncratically creates threads in detached
|
||||
(non-joinable) mode by default.
|
||||
<h2><A name="bigprimebug">
|
||||
Question 5.10. FFTW 2.1.2's complex transforms give incorrect results
|
||||
for large prime sizes.
|
||||
</A></h2>
|
||||
|
||||
This bug was fixed in FFTW 2.1.3. FFTW's complex-transform algorithm
|
||||
for prime sizes (in versions 2.0 to 2.1.2) had an integer overflow
|
||||
problem that caused incorrect results for many primes greater than
|
||||
32768 (on 32-bit machines). (Sizes without large prime factors are
|
||||
not affected.)
|
||||
<h2><A name="solaristhreadbug">
|
||||
Question 5.11. FFTW 2.1.3's multi-threaded transforms don't give any
|
||||
speedup on Solaris.
|
||||
</A></h2>
|
||||
|
||||
This bug was fixed in FFTW 2.1.4. (By default, Solaris creates
|
||||
threads that do not parallelize over multiple processors, so one has
|
||||
to request the proper behavior specifically.)
|
||||
|
||||
<h2><A name="aixflags">
|
||||
Question 5.12. FFTW 2.1.3 crashes on AIX.
|
||||
</A></h2>
|
||||
|
||||
The FFTW 2.1.3 <code>configure</code> script picked incorrect compiler flags for the <code>xlc</code> compiler on newer IBM processors. This
|
||||
is fixed in FFTW 2.1.4. <hr>
|
||||
Back: <a href="section4.html" rev=precedes>Internals of FFTW</a>.<br>
|
||||
<a href="index.html" rev=subdocument>Return to contents</a>.<p>
|
||||
<address>
|
||||
<A href="http://www.fftw.org">Matteo Frigo and Steven G. Johnson</A> / <A href="mailto:fftw@fftw.org">fftw@fftw.org</A>
|
||||
- 14 September 2021
|
||||
</address><br>
|
||||
Extracted from FFTW Frequently Asked Questions with Answers,
|
||||
Copyright © 2021 Matteo Frigo and Massachusetts Institute of Technology.
|
||||
</body></html>
|
||||
7
fftw-3.3.10/doc/FAQ/html.refs
Normal file
7
fftw-3.3.10/doc/FAQ/html.refs
Normal file
@@ -0,0 +1,7 @@
|
||||
\ References for the FFTW FAQ
|
||||
\
|
||||
the FFTW web page \ http://www.fftw.org
|
||||
FFTW Windows installation notes \ http://www.fftw.org/install/windows.html
|
||||
Categories of Free and Non-Free Software \ http://www.gnu.org/philosophy/categories.html
|
||||
the Caml web page \ http://caml.inria.fr
|
||||
pruned FFTs with FFTW \ http://www.fftw.org/pruned.html
|
||||
189
fftw-3.3.10/doc/FAQ/m-ascii.pl
Normal file
189
fftw-3.3.10/doc/FAQ/m-ascii.pl
Normal file
@@ -0,0 +1,189 @@
|
||||
## ASCII output
|
||||
# Copyright (C) 1993-1995 Ian Jackson.
|
||||
|
||||
# This file is free software; you can redistribute it and/or modify
|
||||
# it under the terms of the GNU General Public License as published by
|
||||
# the Free Software Foundation; either version 2, or (at your option)
|
||||
# any later version.
|
||||
|
||||
# It is distributed in the hope that it will be useful,
|
||||
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
# GNU General Public License for more details.
|
||||
|
||||
# You should have received a copy of the GNU General Public License
|
||||
# along with GNU Emacs; see the file COPYING. If not, write to
|
||||
# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||||
# Boston, MA 02111-1307, USA.
|
||||
|
||||
# (Note: I do not consider works produced using these BFNN processing
|
||||
# tools to be derivative works of the tools, so they are NOT covered
|
||||
# by the GPL. However, I would appreciate it if you credited me if
|
||||
# appropriate in any documents you format using BFNN.)
|
||||
|
||||
sub ascii_init {
|
||||
open(ASCII,">$prefix.ascii");
|
||||
}
|
||||
|
||||
sub ascii_startmajorheading {
|
||||
print ASCII '='x79,"\n\n";
|
||||
$ascii_status= 'h';
|
||||
&ascii_text($_[0] ? "Section $_[0]. " : '');
|
||||
}
|
||||
|
||||
sub ascii_startminorheading {
|
||||
print ASCII '-'x79,"\n\n";
|
||||
$ascii_status= 'h';
|
||||
}
|
||||
|
||||
sub ascii_italic { &ascii_text('*'); }
|
||||
sub ascii_enditalic { $ascii_para .= '*'; }
|
||||
|
||||
sub ascii_email { &ascii_text('<'); } sub ascii_endemail { &ascii_text('>'); }
|
||||
|
||||
sub ascii_ftpon { } sub ascii_endftpon { }
|
||||
sub ascii_ftpin { } sub ascii_endftpin { }
|
||||
sub ascii_docref { } sub ascii_enddocref { }
|
||||
sub ascii_courier { } sub ascii_endcourier { }
|
||||
sub ascii_newsgroup { } sub ascii_endnewsgroup { }
|
||||
sub ascii_ftpsilent { $ascii_ignore++; }
|
||||
sub ascii_endftpsilent { $ascii_ignore--; }
|
||||
|
||||
sub ascii_text {
|
||||
return if $ascii_ignore;
|
||||
if ($ascii_status eq '') {
|
||||
$ascii_status= 'p';
|
||||
}
|
||||
$ascii_para .= $_[0];
|
||||
}
|
||||
|
||||
sub ascii_tab {
|
||||
local ($n) = $_[0]-length($ascii_para);
|
||||
$ascii_para .= ' 'x$n if $n>0;
|
||||
}
|
||||
|
||||
sub ascii_newline {
|
||||
return unless $ascii_status eq 'p';
|
||||
&ascii_writepara;
|
||||
}
|
||||
|
||||
sub ascii_writepara {
|
||||
local ($thisline, $thisword, $rest);
|
||||
for (;;) {
|
||||
last unless $ascii_para =~ m/\S/;
|
||||
$thisline= $ascii_indentstring;
|
||||
for (;;) {
|
||||
last unless $ascii_para =~ m/^(\s*\S+)/;
|
||||
unless (length($1) + length($thisline) < 75 ||
|
||||
length($thisline) == length($ascii_indentstring)) {
|
||||
last;
|
||||
}
|
||||
$thisline .= $1;
|
||||
$ascii_para= $';
|
||||
}
|
||||
$ascii_para =~ s/^\s*//;
|
||||
print ASCII $thisline,"\n";
|
||||
$ascii_indentstring= $ascii_nextindent;
|
||||
last unless length($ascii_para);
|
||||
}
|
||||
$ascii_status= ''; $ascii_para= '';
|
||||
}
|
||||
|
||||
sub ascii_endpara {
|
||||
return unless $ascii_status eq 'p';
|
||||
&ascii_writepara;
|
||||
print ASCII "\n";
|
||||
}
|
||||
|
||||
sub ascii_endheading {
|
||||
$ascii_para =~ s/\s*$//;
|
||||
print ASCII "$ascii_para\n\n";
|
||||
$ascii_status= '';
|
||||
$ascii_para= '';
|
||||
}
|
||||
|
||||
sub ascii_endmajorheading { &ascii_endheading(@_); }
|
||||
sub ascii_endminorheading { &ascii_endheading(@_); }
|
||||
|
||||
sub ascii_startverbatim {
|
||||
$ascii_vstatus= $ascii_status;
|
||||
&ascii_writepara;
|
||||
}
|
||||
|
||||
sub ascii_verbatim {
|
||||
print ASCII $_[0],"\n";
|
||||
}
|
||||
|
||||
sub ascii_endverbatim {
|
||||
$ascii_status= $ascii_vstatus;
|
||||
}
|
||||
|
||||
sub ascii_finish {
|
||||
close(ASCII);
|
||||
}
|
||||
|
||||
sub ascii_startindex { $ascii_status= ''; }
|
||||
sub ascii_endindex { $ascii_status= 'p'; }
|
||||
|
||||
sub ascii_endindexitem {
|
||||
printf ASCII " %-11s %-.66s\n",$ascii_left,$ascii_para;
|
||||
$ascii_status= 'p';
|
||||
$ascii_para= '';
|
||||
}
|
||||
|
||||
sub ascii_startindexitem {
|
||||
$ascii_left= $_[1];
|
||||
}
|
||||
|
||||
sub ascii_startindexmainitem {
|
||||
$ascii_left= $_[1];
|
||||
print ASCII "\n" if $ascii_status eq 'p';
|
||||
}
|
||||
|
||||
sub ascii_startindent {
|
||||
$ascii_istatus= $ascii_status;
|
||||
&ascii_writepara;
|
||||
$ascii_indentstring= " $ascii_indentstring";
|
||||
$ascii_nextindent= " $ascii_nextindent";
|
||||
}
|
||||
|
||||
sub ascii_endindent {
|
||||
$ascii_indentstring =~ s/^ //;
|
||||
$ascii_nextindent =~ s/^ //;
|
||||
$ascii_status= $ascii_istatus;
|
||||
}
|
||||
|
||||
sub ascii_startpackedlist { $ascii_plc=0; }
|
||||
sub ascii_endpackedlist { &ascii_newline if !$ascii_plc; }
|
||||
sub ascii_packeditem {
|
||||
&ascii_newline if !$ascii_plc;
|
||||
&ascii_tab($ascii_plc*40+5);
|
||||
$ascii_plc= !$ascii_plc;
|
||||
}
|
||||
|
||||
sub ascii_startlist {
|
||||
&ascii_endpara;
|
||||
$ascii_indentstring= " $ascii_indentstring";
|
||||
$ascii_nextindent= " $ascii_nextindent";
|
||||
}
|
||||
|
||||
sub ascii_endlist {
|
||||
&ascii_endpara;
|
||||
$ascii_indentstring =~ s/^ //;
|
||||
$ascii_nextindent =~ s/^ //;
|
||||
}
|
||||
|
||||
sub ascii_item {
|
||||
&ascii_newline;
|
||||
$ascii_indentstring =~ s/ $/* /;
|
||||
}
|
||||
|
||||
sub ascii_pageref {
|
||||
&ascii_text("Q$_[1] \`");
|
||||
}
|
||||
|
||||
sub ascii_endpageref {
|
||||
&ascii_text("'");
|
||||
}
|
||||
|
||||
1;
|
||||
337
fftw-3.3.10/doc/FAQ/m-html.pl
Normal file
337
fftw-3.3.10/doc/FAQ/m-html.pl
Normal file
@@ -0,0 +1,337 @@
|
||||
## HTML output
|
||||
# Copyright (C) 1993-1995 Ian Jackson.
|
||||
|
||||
# This file is free software; you can redistribute it and/or modify
|
||||
# it under the terms of the GNU General Public License as published by
|
||||
# the Free Software Foundation; either version 2, or (at your option)
|
||||
# any later version.
|
||||
|
||||
# It is distributed in the hope that it will be useful,
|
||||
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
# GNU General Public License for more details.
|
||||
|
||||
# You should have received a copy of the GNU General Public License
|
||||
# along with GNU Emacs; see the file COPYING. If not, write to
|
||||
# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||||
# Boston, MA 02111-1307, USA.
|
||||
|
||||
# (Note: I do not consider works produced using these BFNN processing
|
||||
# tools to be derivative works of the tools, so they are NOT covered
|
||||
# by the GPL. However, I would appreciate it if you credited me if
|
||||
# appropriate in any documents you format using BFNN.)
|
||||
|
||||
%saniarray= ('<','lt', '>','gt', '&','amp', '"','quot');
|
||||
|
||||
sub html_init {
|
||||
$html_prefix = './'.$prefix;
|
||||
$html_prefix =~ s:^\.//:/:;
|
||||
system('rm','-r',"$html_prefix.html");
|
||||
system('mkdir',"$html_prefix.html");
|
||||
open(HTML,">$html_prefix.html/index.html");
|
||||
print HTML "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 3.2//EN\">\n";
|
||||
print HTML "<html>\n";
|
||||
$html_needpara= -1;
|
||||
$html_end='';
|
||||
chop($html_date=`date '+%d %B %Y'`);
|
||||
chop($html_year=`date '+%Y'`);
|
||||
}
|
||||
|
||||
sub html_startup {
|
||||
print HTML <<END;
|
||||
<head><title>
|
||||
$user_title
|
||||
</title>
|
||||
<link rev="made" href="mailto:$user_authormail">
|
||||
<link rel="Contents" href="index.html">
|
||||
<link rel="Start" href="index.html">
|
||||
<META name="description"
|
||||
content="Frequently asked questions and answers (FAQ) for FFTW.">
|
||||
<link rel="Bookmark" title="FFTW FAQ" href="index.html">
|
||||
<LINK rel="Bookmark" title="FFTW Home Page"
|
||||
href="http://www.fftw.org">
|
||||
<LINK rel="Bookmark" title="FFTW Manual"
|
||||
href="http://www.fftw.org/doc/">
|
||||
</head><body text="#000000" bgcolor="#FFFFFF"><h1>
|
||||
$user_title
|
||||
</h1>
|
||||
END
|
||||
&html_readrefs($_[0]);
|
||||
if (length($user_copyrightref)) {
|
||||
local ($refn) = $qrefn{$user_copyrightref};
|
||||
if (!length($refn)) {
|
||||
warn "unknown question (copyright) `$user_copyrightref'";
|
||||
}
|
||||
$refn =~ m/(\d+)\.(\d+)/;
|
||||
local ($s,$n) = ($1,$2);
|
||||
$html_copyrighthref= ($s == $html_sectionn)?'':"section$s.html";
|
||||
$html_copyrighthref.= "#$qn2ref{$s,$n}";
|
||||
}
|
||||
}
|
||||
|
||||
sub html_close {
|
||||
print HTML $html_end,"<address>\n$user_author\n";
|
||||
print HTML "- $html_date\n</address><br>\n";
|
||||
print HTML "Extracted from $user_title,\n";
|
||||
print HTML "<A href=\"$html_copyrighthref\">" if length($html_copyrighthref);
|
||||
print HTML "Copyright © $html_year $user_copyholder.";
|
||||
print HTML "</A>" if length($html_copyrighthref);
|
||||
print HTML "\n</body></html>\n";
|
||||
close(HTML);
|
||||
}
|
||||
|
||||
sub html_startmajorheading {
|
||||
local ($ref, $this,$next,$back) = @_;
|
||||
local ($nextt,$backt);
|
||||
$this =~ s/^Section /section/; $html_sectionn= $ref;
|
||||
$next =~ s/^Section /section/ && ($nextt= $sn2title{$'});
|
||||
$back =~ s/^Section /section/ ? ($backt= $sn2title{$'}) : ($back='');
|
||||
if ($html_sectionn) {
|
||||
&html_close;
|
||||
open(HTML,">$html_prefix.html/$this.html");
|
||||
print HTML "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 3.2//EN\">\n";
|
||||
print HTML "<html>\n";
|
||||
$html_end= "<hr>\n";
|
||||
$html_end.= "Next: <a href=\"$next.html\" rel=precedes>$nextt</a>.<br>\n"
|
||||
if $next;
|
||||
$html_end.= "Back: <a href=\"$back.html\" rev=precedes>$backt</a>.<br>\n"
|
||||
if $back;
|
||||
$html_end.= "<a href=\"index.html\" rev=subdocument>";
|
||||
$html_end.= "Return to contents</a>.<p>\n";
|
||||
print HTML <<END;
|
||||
<head><title>
|
||||
$user_brieftitle - Section $html_sectionn
|
||||
</title>
|
||||
<link rev="made" href="mailto:$user_authormail">
|
||||
<link rel="Contents" href="index.html">
|
||||
<link rel="Start" href="index.html">
|
||||
END
|
||||
print HTML "<link rel=\"Next\" href=\"$next.html\">" if $next;
|
||||
print HTML "<link rel=\"Previous\" href=\"$back.html\">" if $back;
|
||||
print HTML <<END;
|
||||
<link rel="Bookmark" title="FFTW FAQ" href="index.html">
|
||||
</head><body text="#000000" bgcolor="#FFFFFF"><h1>
|
||||
$user_brieftitle - Section $html_sectionn <br>
|
||||
END
|
||||
$html_needpara= -1;
|
||||
}
|
||||
else {
|
||||
print HTML "\n<h1>\n";
|
||||
$html_needpara=-1;
|
||||
}
|
||||
}
|
||||
|
||||
sub html_endmajorheading {
|
||||
print HTML "\n</h1>\n\n";
|
||||
$html_needpara=-1;
|
||||
}
|
||||
|
||||
sub html_startminorheading {
|
||||
local ($ref, $this) = @_;
|
||||
$html_needpara=0;
|
||||
$this =~ m/^Question (\d+)\.(\d+)/;
|
||||
local ($s,$n) = ($1,$2);
|
||||
print HTML "\n<h2><A name=\"$qn2ref{$s,$n}\">\n";
|
||||
}
|
||||
|
||||
sub html_endminorheading {
|
||||
print HTML "\n</A></h2>\n\n";
|
||||
$html_needpara=-1;
|
||||
}
|
||||
|
||||
sub html_newsgroup { &arg('newsgroup'); }
|
||||
sub html_endnewsgroup { &endarg('newsgroup'); }
|
||||
sub html_do_newsgroup {
|
||||
print HTML "<A href=\"news:$_[0]\"><code>$_[0]</code></A>";
|
||||
}
|
||||
|
||||
sub html_email { &arg('email'); }
|
||||
sub html_endemail { &endarg('email'); }
|
||||
sub html_do_email {
|
||||
print HTML "<A href=\"mailto:$_[0]\"><code>$_[0]</code></A>";
|
||||
}
|
||||
|
||||
sub html_courier { print HTML "<code>" ; }
|
||||
sub html_endcourier { print HTML "</code>"; }
|
||||
sub html_italic { print HTML "<i>" ; }
|
||||
sub html_enditalic { print HTML "</i>" ; }
|
||||
|
||||
sub html_docref { &arg('docref'); }
|
||||
sub html_enddocref { &endarg('docref'); }
|
||||
sub html_do_docref {
|
||||
if (!defined($html_refval{$_[0]})) {
|
||||
warn "undefined HTML reference $_[0]";
|
||||
$html_refval{$n}='UNDEFINED';
|
||||
}
|
||||
print HTML "<A href=\"$html_refval{$_[0]}\">";
|
||||
&recurse($_[0]);
|
||||
print HTML "</A>";
|
||||
}
|
||||
|
||||
sub html_readrefs {
|
||||
local ($p);
|
||||
open(HTMLREFS,"<$_[0]") || (warn("failed to open HTML refs $_[0]: $!"),return);
|
||||
while(<HTMLREFS>) {
|
||||
next if m/^\\\s/;
|
||||
s/\s*\n$//;
|
||||
if (s/^\\prefix\s*//) {
|
||||
$p= $'; next;
|
||||
} elsif (s/^\s*(\S.*\S)\s*\\\s*//) {
|
||||
$_=$1; $v=$';
|
||||
s/\\\\/\\/g;
|
||||
$html_refval{$_}= $p.$v;
|
||||
} else {
|
||||
warn("ununderstood line in HTML refs >$_<");
|
||||
}
|
||||
}
|
||||
close(HTMLREFS);
|
||||
}
|
||||
|
||||
sub html_ftpsilent { &arg('ftpsilent'); }
|
||||
sub html_endftpsilent { &endarg('ftpsilent'); }
|
||||
sub html_do_ftpsilent {
|
||||
if ($_[0] =~ m/:/) {
|
||||
$html_ftpsite= $`;
|
||||
$html_ftpdir= $'.'/';
|
||||
} else {
|
||||
$html_ftpsite= $_[0];
|
||||
$html_ftpdir= '';
|
||||
}
|
||||
}
|
||||
|
||||
sub html_ftpon { &arg('ftpon'); }
|
||||
sub html_endftpon { &endarg('ftpon'); }
|
||||
sub html_do_ftpon {
|
||||
#print STDERR "ftpon($_[0])\n";
|
||||
$html_ftpsite= $_[0]; $html_ftpdir= '';
|
||||
print HTML "<code>";
|
||||
&recurse($_[0]);
|
||||
print HTML "</code>";
|
||||
}
|
||||
|
||||
sub html_ftpin { &arg('ftpin'); }
|
||||
sub html_endftpin { &endarg('ftpin'); }
|
||||
sub html_do_ftpin {
|
||||
#print STDERR "ftpin($_[0])\n";
|
||||
print HTML "<A href=\"ftp://$html_ftpsite$html_ftpdir$_[0]\"><code>";
|
||||
&recurse($_[0]);
|
||||
print HTML "</code></A>";
|
||||
}
|
||||
|
||||
sub html_text {
|
||||
print HTML "\n<p>\n" if $html_needpara > 0;
|
||||
$html_needpara=0;
|
||||
$html_stuff= &html_sanitise($_[0]);
|
||||
while ($html_stuff =~ s/^(.{40,70}) //) {
|
||||
print HTML "$1\n";
|
||||
}
|
||||
print HTML $html_stuff;
|
||||
}
|
||||
|
||||
sub html_tab {
|
||||
$htmltabignore++ || warn "html tab ignored";
|
||||
}
|
||||
|
||||
sub html_newline { print HTML "<br>\n" ; }
|
||||
sub html_startverbatim { print HTML "<pre>\n" ; }
|
||||
sub html_verbatim { print HTML &html_sanitise($_[0]),"\n"; }
|
||||
sub html_endverbatim { print HTML "</pre>\n" ; $html_needpara= -1; }
|
||||
|
||||
sub html_endpara {
|
||||
$html_needpara || $html_needpara++;
|
||||
}
|
||||
|
||||
sub html_finish {
|
||||
&html_close;
|
||||
}
|
||||
|
||||
sub html_startindex {
|
||||
print HTML "<ul>\n";
|
||||
}
|
||||
|
||||
sub html_endindex {
|
||||
print HTML "</ul><hr>\n";
|
||||
}
|
||||
|
||||
sub html_startindexitem {
|
||||
local ($ref,$qval) = @_;
|
||||
$qval =~ m/Q(\d+)\.(\d+)/;
|
||||
local ($s,$n) = ($1,$2);
|
||||
print HTML "<li><a href=\"";
|
||||
print HTML ($s == $html_sectionn)?'':"section$s.html";
|
||||
print HTML "#$qn2ref{$s,$n}\" rel=subdocument>Q$s.$n. ";
|
||||
$html_indexunhead='';
|
||||
}
|
||||
|
||||
sub html_startindexmainitem {
|
||||
local ($ref,$s) = @_;
|
||||
$s =~ m/\d+/; $s= $&;
|
||||
print HTML "<br><br>" if ($s > 1);
|
||||
print HTML "<li><b><font size=\"+2\"><a href=\"section$s.html\" rel=subdocument>Section $s. ";
|
||||
$html_indexunhead='</font></b>';
|
||||
}
|
||||
|
||||
sub html_endindexitem {
|
||||
print HTML "</a>$html_indexunhead\n";
|
||||
}
|
||||
|
||||
sub html_startlist {
|
||||
print HTML "\n";
|
||||
$html_itemend="<ul>";
|
||||
}
|
||||
|
||||
sub html_endlist {
|
||||
print HTML "$html_itemend\n</ul>\n";
|
||||
$html_needpara=-1
|
||||
}
|
||||
|
||||
sub html_item {
|
||||
print HTML "$html_itemend\n<li>";
|
||||
$html_itemend="";
|
||||
$html_needpara=-1;
|
||||
}
|
||||
|
||||
sub html_startpackedlist {
|
||||
print HTML "\n";
|
||||
$html_itemend="<dir>";
|
||||
}
|
||||
|
||||
sub html_endpackedlist {
|
||||
print HTML "$html_itemend\n</dir>\n";
|
||||
$html_needpara=-1;
|
||||
}
|
||||
|
||||
sub html_packeditem {
|
||||
print HTML "$html_itemend\n<li>";
|
||||
$html_itemend="";
|
||||
$html_needpara=-1;
|
||||
}
|
||||
|
||||
sub html_startindent { print HTML "<blockquote>\n"; }
|
||||
sub html_endindent { print HTML "</blockquote>\n"; }
|
||||
|
||||
sub html_pageref {
|
||||
local ($ref,$sq) = @_;
|
||||
$sq =~ m/(\d+)\.(\d+)/;
|
||||
local ($s,$n) = ($1,$2);
|
||||
print HTML "<A href=\"";
|
||||
print HTML ($s == $html_sectionn)?'':"section$s.html";
|
||||
print HTML "#$qn2ref{$s,$n}\">Q$sq \`";
|
||||
}
|
||||
|
||||
sub html_endpageref {
|
||||
print HTML "'</A>";
|
||||
}
|
||||
|
||||
sub html_sanitise {
|
||||
local ($in) = @_;
|
||||
local ($out);
|
||||
while ($in =~ m/[<>&"]/) {
|
||||
$out.= $`. '&'. $saniarray{$&}. ';';
|
||||
$in=$';
|
||||
}
|
||||
$out.= $in;
|
||||
$out;
|
||||
}
|
||||
|
||||
1;
|
||||
226
fftw-3.3.10/doc/FAQ/m-info.pl
Normal file
226
fftw-3.3.10/doc/FAQ/m-info.pl
Normal file
@@ -0,0 +1,226 @@
|
||||
## Info output
|
||||
# Copyright (C) 1993-1995 Ian Jackson.
|
||||
|
||||
# This file is free software; you can redistribute it and/or modify
|
||||
# it under the terms of the GNU General Public License as published by
|
||||
# the Free Software Foundation; either version 2, or (at your option)
|
||||
# any later version.
|
||||
|
||||
# It is distributed in the hope that it will be useful,
|
||||
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
# GNU General Public License for more details.
|
||||
|
||||
# You should have received a copy of the GNU General Public License
|
||||
# along with GNU Emacs; see the file COPYING. If not, write to
|
||||
# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||||
# Boston, MA 02111-1307, USA.
|
||||
|
||||
# (Note: I do not consider works produced using these BFNN processing
|
||||
# tools to be derivative works of the tools, so they are NOT covered
|
||||
# by the GPL. However, I would appreciate it if you credited me if
|
||||
# appropriate in any documents you format using BFNN.)
|
||||
|
||||
sub info_init {
|
||||
open(INFO,">$prefix.info");
|
||||
print INFO <<END;
|
||||
Info file: $prefix.info, -*-Text-*-
|
||||
produced by bfnnconv.pl from the Bizarre Format With No Name.
|
||||
|
||||
END
|
||||
}
|
||||
|
||||
sub info_heading {
|
||||
# refstring Node Next Previous Up
|
||||
print INFO " \nFile: $prefix.info, Node: $_[1]";
|
||||
print INFO ", Next: $_[2]" if length($_[2]);
|
||||
print INFO ", Previous: $_[3]" if length($_[3]);
|
||||
print INFO ", Up: $_[4]" if length($_[4]);
|
||||
print INFO "\n\n";
|
||||
$info_status= '';
|
||||
}
|
||||
|
||||
sub info_startmajorheading {
|
||||
return if $_[0] eq '0';
|
||||
&info_heading('s_'.$_[0],@_[1..$#_],'Top');
|
||||
}
|
||||
|
||||
sub info_startminorheading {
|
||||
&info_heading(@_);
|
||||
}
|
||||
|
||||
sub info_italic { &info_text('*'); }
|
||||
sub info_enditalic { $info_para .= '*'; }
|
||||
|
||||
sub info_email { &info_text('<'); } sub info_endemail { &info_text('>'); }
|
||||
|
||||
sub info_ftpon { } sub info_endftpon { }
|
||||
sub info_ftpin { } sub info_endftpin { }
|
||||
sub info_docref { } sub info_enddocref { }
|
||||
sub info_courier { } sub info_endcourier { }
|
||||
sub info_newsgroup { } sub info_endnewsgroup { }
|
||||
sub info_ftpsilent { $info_ignore++; }
|
||||
sub info_endftpsilent { $info_ignore--; }
|
||||
|
||||
sub info_text {
|
||||
return if $info_ignore;
|
||||
if ($info_status eq '') {
|
||||
$info_status= 'p';
|
||||
}
|
||||
$info_para .= $_[0];
|
||||
}
|
||||
|
||||
sub info_tab {
|
||||
local ($n) = $_[0]-length($info_para);
|
||||
$info_para .= ' 'x$n if $n>0;
|
||||
}
|
||||
|
||||
sub info_newline {
|
||||
return unless $info_status eq 'p';
|
||||
print INFO &info_writepara;
|
||||
}
|
||||
|
||||
sub info_writepara {
|
||||
local ($thisline, $thisword, $rest, $output);
|
||||
for (;;) {
|
||||
last unless $info_para =~ m/\S/;
|
||||
$thisline= $info_indentstring;
|
||||
for (;;) {
|
||||
last unless $info_para =~ m/^(\s*\S+)/;
|
||||
unless (length($1) + length($thisline) < 75 ||
|
||||
length($thisline) == length($info_indentstring)) {
|
||||
last;
|
||||
}
|
||||
$thisline .= $1;
|
||||
$info_para= $';
|
||||
}
|
||||
$info_para =~ s/^\s*//;
|
||||
$output.= $thisline."\n";
|
||||
$info_indentstring= $info_nextindent;
|
||||
last unless length($info_para);
|
||||
}
|
||||
$info_status= ''; $info_para= '';
|
||||
return $output;
|
||||
}
|
||||
|
||||
sub info_endpara {
|
||||
return unless $info_status eq 'p';
|
||||
print INFO &info_writepara;
|
||||
print INFO "\n";
|
||||
}
|
||||
|
||||
sub info_endheading {
|
||||
$info_para =~ s/\s*$//;
|
||||
print INFO "$info_para\n\n";
|
||||
$info_status= '';
|
||||
$info_para= '';
|
||||
}
|
||||
|
||||
sub info_endmajorheading { &info_endheading(@_); }
|
||||
sub info_endminorheading { &info_endheading(@_); }
|
||||
|
||||
sub info_startverbatim {
|
||||
print INFO &info_writepara;
|
||||
}
|
||||
|
||||
sub info_verbatim {
|
||||
print INFO $_[0],"\n";
|
||||
}
|
||||
|
||||
sub info_endverbatim {
|
||||
$info_status= $info_vstatus;
|
||||
}
|
||||
|
||||
sub info_finish {
|
||||
close(INFO);
|
||||
}
|
||||
|
||||
sub info_startindex {
|
||||
&info_endpara;
|
||||
$info_moredetail= '';
|
||||
$info_status= '';
|
||||
}
|
||||
|
||||
sub info_endindex {
|
||||
print INFO "$info_moredetail\n" if length($info_moredetail);
|
||||
}
|
||||
|
||||
sub info_endindexitem {
|
||||
$info_indentstring= sprintf("* %-17s ",$info_label.'::');
|
||||
$info_nextindent= ' 'x20;
|
||||
local ($txt);
|
||||
$txt= &info_writepara;
|
||||
if ($info_main) {
|
||||
print INFO $label.$txt;
|
||||
$txt =~ s/^.{20}//;
|
||||
$info_moredetail.= $txt;
|
||||
} else {
|
||||
$info_moredetail.= $label.$txt;
|
||||
}
|
||||
$info_indentstring= $info_nextindent= '';
|
||||
$info_status='p';
|
||||
}
|
||||
|
||||
sub info_startindexitem {
|
||||
print INFO "* Menu:\n" if $info_status eq '';
|
||||
$info_status= '';
|
||||
$info_label= $_[2];
|
||||
$info_main= 0;
|
||||
}
|
||||
|
||||
sub info_startindexmainitem {
|
||||
print INFO "* Menu:\n" if $info_status eq '';
|
||||
$info_label= $_[2];
|
||||
$info_main= 1;
|
||||
$info_moredetail .= "\n$_[2], ";
|
||||
$info_status= '';
|
||||
}
|
||||
|
||||
sub info_startindent {
|
||||
$info_istatus= $info_status;
|
||||
print INFO &info_writepara;
|
||||
$info_indentstring= " $info_indentstring";
|
||||
$info_nextindent= " $info_nextindent";
|
||||
}
|
||||
|
||||
sub info_endindent {
|
||||
$info_indentstring =~ s/^ //;
|
||||
$info_nextindent =~ s/^ //;
|
||||
$info_status= $info_istatus;
|
||||
}
|
||||
|
||||
sub info_startpackedlist { $info_plc=0; }
|
||||
sub info_endpackedlist { &info_newline if !$info_plc; }
|
||||
sub info_packeditem {
|
||||
&info_newline if !$info_plc;
|
||||
&info_tab($info_plc*40+5);
|
||||
$info_plc= !$info_plc;
|
||||
}
|
||||
|
||||
sub info_startlist {
|
||||
$info_istatus= $info_status;
|
||||
print INFO &info_writepara;
|
||||
$info_indentstring= " $info_indentstring";
|
||||
$info_nextindent= " $info_nextindent";
|
||||
}
|
||||
|
||||
sub info_endlist {
|
||||
$info_indentstring =~ s/^ //;
|
||||
$info_nextindent =~ s/^ //;
|
||||
$info_status= $info_lstatus;
|
||||
}
|
||||
|
||||
sub info_item {
|
||||
&info_newline;
|
||||
$info_indentstring =~ s/ $/* /;
|
||||
}
|
||||
|
||||
sub info_pageref {
|
||||
&info_text("*Note Question $_[1]:: \`");
|
||||
}
|
||||
|
||||
sub info_endpageref {
|
||||
&info_text("'");
|
||||
}
|
||||
|
||||
1;
|
||||
242
fftw-3.3.10/doc/FAQ/m-lout.pl
Normal file
242
fftw-3.3.10/doc/FAQ/m-lout.pl
Normal file
@@ -0,0 +1,242 @@
|
||||
## Lout output
|
||||
# Copyright (C) 1993-1995 Ian Jackson.
|
||||
|
||||
# This file is free software; you can redistribute it and/or modify
|
||||
# it under the terms of the GNU General Public License as published by
|
||||
# the Free Software Foundation; either version 2, or (at your option)
|
||||
# any later version.
|
||||
|
||||
# It is distributed in the hope that it will be useful,
|
||||
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
# GNU General Public License for more details.
|
||||
|
||||
# You should have received a copy of the GNU General Public License
|
||||
# along with GNU Emacs; see the file COPYING. If not, write to
|
||||
# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||||
# Boston, MA 02111-1307, USA.
|
||||
|
||||
# (Note: I do not consider works produced using these BFNN processing
|
||||
# tools to be derivative works of the tools, so they are NOT covered
|
||||
# by the GPL. However, I would appreciate it if you credited me if
|
||||
# appropriate in any documents you format using BFNN.)
|
||||
|
||||
sub lout_init {
|
||||
open(LOUT,">$prefix.lout");
|
||||
chop($dprint= `date '+%d %B %Y'`);
|
||||
$dprint =~ s/^0//;
|
||||
}
|
||||
|
||||
sub lout_startup {
|
||||
local ($lbs) = &lout_sanitise($user_brieftitle);
|
||||
print LOUT <<END;
|
||||
\@SysInclude{ fontdefs }
|
||||
\@SysInclude{ langdefs }
|
||||
\@SysInclude{ dl }
|
||||
\@SysInclude{ docf }
|
||||
\@Use { \@DocumentLayout
|
||||
\@OddTop { \@Null }
|
||||
\@EvenTop { \@Null }
|
||||
\@StartOddTop { \@Null }
|
||||
\@StartEvenTop { \@Null }
|
||||
\@OddFoot { { $lbs } \@Centre{ - \@PageNum - } \@Right{ $dprint } }
|
||||
\@EvenFoot { { $lbs } \@Centre{ - \@PageNum - } \@Right{ $dprint } }
|
||||
\@StartOddFoot { { $lbs } \@Centre{ - \@PageNum - } \@Right{ $dprint } }
|
||||
\@StartEvenFoot { { $lbs } \@Centre{ - \@PageNum - } \@Right{ $dprint } }
|
||||
\@ParaGap { 1.70vx }
|
||||
\@InitialBreak { 1.0fx ragged hyphen }
|
||||
}
|
||||
\@Use { \@OrdinaryLayout }
|
||||
END
|
||||
$lout_textstatus= 'p';
|
||||
}
|
||||
|
||||
sub lout_pageref {
|
||||
print LOUT "Q$_[1] (page {\@PageOf{$_[0]}}) ";
|
||||
&lout_text("\`");
|
||||
}
|
||||
|
||||
sub lout_endpageref {
|
||||
&lout_text("'");
|
||||
}
|
||||
|
||||
sub lout_finish {
|
||||
print LOUT "\@End \@Text\n";
|
||||
close(L);
|
||||
}
|
||||
|
||||
sub lout_startmajorheading {
|
||||
$lout_styles .= 'h';
|
||||
print LOUT <<END
|
||||
\@CNP
|
||||
{
|
||||
newpath 0 ysize 0.3 ft sub moveto
|
||||
xsize 0 rlineto
|
||||
0 0.2 ft rlineto
|
||||
xsize neg 0 rlineto
|
||||
closepath fill
|
||||
} \@Graphic { //1.6f \@HAdjust \@Heading{
|
||||
END
|
||||
;
|
||||
$endh= "}\n{\@PageMark s_$_[0]}\n/1.0fo\n";
|
||||
&lout_text($_[0] ? "Section $_[0]. " : '');
|
||||
}
|
||||
|
||||
sub lout_startminorheading {
|
||||
$lout_styles .= 'h';
|
||||
print LOUT "//0.2f \@CNP {\@PageMark $_[0]} \@Heading{\n";
|
||||
$endh= '';
|
||||
}
|
||||
|
||||
sub lout_endheading {
|
||||
$lout_styles =~ s/.$//; print LOUT "}\n$endh";
|
||||
$lout_status= 'p';
|
||||
}
|
||||
|
||||
sub lout_endmajorheading { &lout_endheading(@_); }
|
||||
sub lout_endminorheading { &lout_endheading(@_); }
|
||||
|
||||
sub lout_courier {
|
||||
$lout_styles .= 'f';
|
||||
print LOUT "{{0.7 1.0} \@Scale {Courier Bold} \@Font {";
|
||||
}
|
||||
|
||||
sub lout_endcourier {
|
||||
$lout_styles =~ s/.$//; print LOUT "}}";
|
||||
}
|
||||
|
||||
sub lout_italic { $lout_styles .= 'f'; print LOUT "{Slope \@Font {"; }
|
||||
sub lout_enditalic { $lout_styles =~ s/.$//; print LOUT "}}"; }
|
||||
|
||||
sub lout_startindent { $lout_styles .= 'i'; print LOUT "\@IndentedDisplay {\n"; }
|
||||
|
||||
sub lout_endindent {
|
||||
&lout_endpara;
|
||||
$lout_styles =~ s/.$//; print LOUT "}\n\@LP\n";
|
||||
}
|
||||
|
||||
sub lout_startpackedlist { $lout_plc=-1; }
|
||||
sub lout_endpackedlist { &lout_newline if !$lout_plc; }
|
||||
sub lout_packeditem {
|
||||
&lout_newline if !$lout_plc;
|
||||
&lout_tab(($lout_plc>0)*40+5);
|
||||
$lout_plc= !$lout_plc;
|
||||
}
|
||||
|
||||
sub lout_startlist {
|
||||
&lout_endpara;
|
||||
print LOUT "\@RawIndentedList style {\@Bullet} indent {0.5i} gap {1.1vx}\n";
|
||||
$lout_styles .= 'l';
|
||||
$lout_status= '';
|
||||
}
|
||||
|
||||
sub lout_endlist {
|
||||
&lout_endpara;
|
||||
print LOUT "\@EndList\n\n";
|
||||
$lout_styles =~ s/.$//;
|
||||
}
|
||||
|
||||
sub lout_item {
|
||||
&lout_endpara;
|
||||
print LOUT "\@ListItem{";
|
||||
$lout_styles.= 'I';
|
||||
}
|
||||
|
||||
sub lout_startindex {
|
||||
print LOUT "//0.0fe\n";
|
||||
}
|
||||
|
||||
sub lout_endindex {
|
||||
$lout_status='p';
|
||||
}
|
||||
|
||||
sub lout_startindexmainitem {
|
||||
$lout_marker= $_[0];
|
||||
$lout_status= '';
|
||||
print LOUT "//0.3vx Bold \@Font \@HAdjust { \@HContract { { $_[1] } |3cx {";
|
||||
$lout_iiendheight= '1.00';
|
||||
$lout_styles .= 'X';
|
||||
}
|
||||
|
||||
sub lout_startindexitem {
|
||||
$lout_marker= $_[0];
|
||||
print LOUT "\@HAdjust { \@HContract { { $_[1] } |3cx {";
|
||||
$lout_iiendheight= '0.95';
|
||||
$lout_styles .= 'X';
|
||||
}
|
||||
|
||||
sub lout_endindexitem {
|
||||
print LOUT "} } |0c \@PageOf { $lout_marker } } //${lout_iiendheight}vx\n";
|
||||
$lout_styles =~ s/.$//;
|
||||
}
|
||||
|
||||
sub lout_email { &lout_courier; &lout_text('<'); }
|
||||
sub lout_endemail { &lout_text('>'); &lout_endcourier; }
|
||||
|
||||
sub lout_ftpon { &lout_courier; } sub lout_endftpon { &lout_endcourier; }
|
||||
sub lout_ftpin { &lout_courier; } sub lout_endftpin { &lout_endcourier; }
|
||||
sub lout_docref { } sub lout_enddocref { }
|
||||
sub lout_ftpsilent { $lout_ignore++; }
|
||||
sub lout_endftpsilent { $lout_ignore--; }
|
||||
|
||||
sub lout_newsgroup { &lout_courier; }
|
||||
sub lout_endnewsgroup { &lout_endcourier; }
|
||||
|
||||
sub lout_text {
|
||||
return if $lout_ignore;
|
||||
$lout_status= 'p';
|
||||
$_= &lout_sanitise($_[0]);
|
||||
s/ $/\n/ unless $lout_styles =~ m/[fhX]/;
|
||||
print LOUT $_;
|
||||
}
|
||||
|
||||
sub lout_tab {
|
||||
local ($size) = $_[0]*0.5;
|
||||
print LOUT " |${size}ft ";
|
||||
}
|
||||
|
||||
sub lout_newline {
|
||||
print LOUT " //1.0vx\n";
|
||||
}
|
||||
|
||||
sub lout_sanitise {
|
||||
local ($in) = @_;
|
||||
local ($out);
|
||||
$in= ' '.$in.' ';
|
||||
$out='';
|
||||
while ($in =~ m/(\s)(\S*[\@\/|\\\"\^\&\{\}\#]\S*)(\s)/) {
|
||||
$out .= $`.$1;
|
||||
$in = $3.$';
|
||||
$_= $2;
|
||||
s/[\\\"]/\\$&/g;
|
||||
$out .= '"'.$_.'"';
|
||||
}
|
||||
$out .= $in;
|
||||
$out =~ s/^ //; $out =~ s/ $//;
|
||||
$out;
|
||||
}
|
||||
|
||||
sub lout_endpara {
|
||||
return if $lout_status eq '';
|
||||
if ($lout_styles eq '') {
|
||||
print LOUT "\@LP\n\n";
|
||||
} elsif ($lout_styles =~ s/I$//) {
|
||||
print LOUT "}\n";
|
||||
}
|
||||
$lout_status= '';
|
||||
}
|
||||
|
||||
sub lout_startverbatim {
|
||||
print LOUT "//0.4f\n\@RawIndentedDisplay lines \@Break".
|
||||
" { {0.7 1.0} \@Scale {Courier Bold} \@Font {\n";
|
||||
}
|
||||
|
||||
sub lout_verbatim {
|
||||
$_= $_[0];
|
||||
s/^\s*//;
|
||||
print LOUT &lout_sanitise($_),"\n";
|
||||
}
|
||||
|
||||
sub lout_endverbatim { print LOUT "}\n}\n//0.4f\n"; }
|
||||
|
||||
1;
|
||||
189
fftw-3.3.10/doc/FAQ/m-post.pl
Normal file
189
fftw-3.3.10/doc/FAQ/m-post.pl
Normal file
@@ -0,0 +1,189 @@
|
||||
## POST output
|
||||
# Copyright (C) 1993-1995 Ian Jackson.
|
||||
|
||||
# This file is free software; you can redistribute it and/or modify
|
||||
# it under the terms of the GNU General Public License as published by
|
||||
# the Free Software Foundation; either version 2, or (at your option)
|
||||
# any later version.
|
||||
|
||||
# It is distributed in the hope that it will be useful,
|
||||
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
# GNU General Public License for more details.
|
||||
|
||||
# You should have received a copy of the GNU General Public License
|
||||
# along with GNU Emacs; see the file COPYING. If not, write to
|
||||
# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||||
# Boston, MA 02111-1307, USA.
|
||||
|
||||
# (Note: I do not consider works produced using these BFNN processing
|
||||
# tools to be derivative works of the tools, so they are NOT covered
|
||||
# by the GPL. However, I would appreciate it if you credited me if
|
||||
# appropriate in any documents you format using BFNN.)
|
||||
|
||||
sub post_init {
|
||||
open(POST,">$prefix.post");
|
||||
}
|
||||
|
||||
sub post_startmajorheading {
|
||||
print POST '='x79,"\n\n";
|
||||
$post_status= 'h';
|
||||
&post_text($_[0] ? "Section $_[0]. " : '');
|
||||
}
|
||||
|
||||
sub post_startminorheading {
|
||||
print POST '-'x77,"\n\n";
|
||||
$post_status= 'h';
|
||||
}
|
||||
|
||||
sub post_italic { &post_text('*'); }
|
||||
sub post_enditalic { $post_para .= '*'; }
|
||||
|
||||
sub post_email { &post_text('<'); } sub post_endemail { &post_text('>'); }
|
||||
|
||||
sub post_ftpon { } sub post_endftpon { }
|
||||
sub post_ftpin { } sub post_endftpin { }
|
||||
sub post_docref { } sub post_enddocref { }
|
||||
sub post_courier { } sub post_endcourier { }
|
||||
sub post_newsgroup { } sub post_endnewsgroup { }
|
||||
sub post_ftpsilent { $post_ignore++; }
|
||||
sub post_endftpsilent { $post_ignore--; }
|
||||
|
||||
sub post_text {
|
||||
return if $post_ignore;
|
||||
if ($post_status eq '') {
|
||||
$post_status= 'p';
|
||||
}
|
||||
$post_para .= $_[0];
|
||||
}
|
||||
|
||||
sub post_tab {
|
||||
local ($n) = $_[0]-length($post_para);
|
||||
$post_para .= ' 'x$n if $n>0;
|
||||
}
|
||||
|
||||
sub post_newline {
|
||||
return unless $post_status eq 'p';
|
||||
&post_writepara;
|
||||
}
|
||||
|
||||
sub post_writepara {
|
||||
local ($thisline, $thisword, $rest);
|
||||
for (;;) {
|
||||
last unless $post_para =~ m/\S/;
|
||||
$thisline= $post_indentstring;
|
||||
for (;;) {
|
||||
last unless $post_para =~ m/^(\s*\S+)/;
|
||||
unless (length($1) + length($thisline) < 75 ||
|
||||
length($thisline) == length($post_indentstring)) {
|
||||
last;
|
||||
}
|
||||
$thisline .= $1;
|
||||
$post_para= $';
|
||||
}
|
||||
$post_para =~ s/^\s*//;
|
||||
print POST $thisline,"\n";
|
||||
$post_indentstring= $post_nextindent;
|
||||
last unless length($post_para);
|
||||
}
|
||||
$post_status= ''; $post_para= '';
|
||||
}
|
||||
|
||||
sub post_endpara {
|
||||
return unless $post_status eq 'p';
|
||||
&post_writepara;
|
||||
print POST "\n";
|
||||
}
|
||||
|
||||
sub post_endheading {
|
||||
$post_para =~ s/\s*$//;
|
||||
print POST "$post_para\n\n";
|
||||
$post_status= '';
|
||||
$post_para= '';
|
||||
}
|
||||
|
||||
sub post_endmajorheading { &post_endheading(@_); }
|
||||
sub post_endminorheading { &post_endheading(@_); }
|
||||
|
||||
sub post_startverbatim {
|
||||
$post_vstatus= $post_status;
|
||||
&post_writepara;
|
||||
}
|
||||
|
||||
sub post_verbatim {
|
||||
print POST $_[0],"\n";
|
||||
}
|
||||
|
||||
sub post_endverbatim {
|
||||
$post_status= $post_vstatus;
|
||||
}
|
||||
|
||||
sub post_finish {
|
||||
close(POST);
|
||||
}
|
||||
|
||||
sub post_startindex { $post_status= ''; }
|
||||
sub post_endindex { $post_status= 'p'; }
|
||||
|
||||
sub post_endindexitem {
|
||||
printf POST " %-11s %-.66s\n",$post_left,$post_para;
|
||||
$post_status= 'p';
|
||||
$post_para= '';
|
||||
}
|
||||
|
||||
sub post_startindexitem {
|
||||
$post_left= $_[1];
|
||||
}
|
||||
|
||||
sub post_startindexmainitem {
|
||||
$post_left= $_[1];
|
||||
print POST "\n" if $post_status eq 'p';
|
||||
}
|
||||
|
||||
sub post_startindent {
|
||||
$post_istatus= $post_status;
|
||||
&post_writepara;
|
||||
$post_indentstring= " $post_indentstring";
|
||||
$post_nextindent= " $post_nextindent";
|
||||
}
|
||||
|
||||
sub post_endindent {
|
||||
$post_indentstring =~ s/^ //;
|
||||
$post_nextindent =~ s/^ //;
|
||||
$post_status= $post_istatus;
|
||||
}
|
||||
|
||||
sub post_startpackedlist { $post_plc=0; }
|
||||
sub post_endpackedlist { &post_newline if !$post_plc; }
|
||||
sub post_packeditem {
|
||||
&post_newline if !$post_plc;
|
||||
&post_tab($post_plc*40+5);
|
||||
$post_plc= !$post_plc;
|
||||
}
|
||||
|
||||
sub post_startlist {
|
||||
&post_endpara;
|
||||
$post_indentstring= " $post_indentstring";
|
||||
$post_nextindent= " $post_nextindent";
|
||||
}
|
||||
|
||||
sub post_endlist {
|
||||
&post_endpara;
|
||||
$post_indentstring =~ s/^ //;
|
||||
$post_nextindent =~ s/^ //;
|
||||
}
|
||||
|
||||
sub post_item {
|
||||
&post_newline;
|
||||
$post_indentstring =~ s/ $/* /;
|
||||
}
|
||||
|
||||
sub post_pageref {
|
||||
&post_text("Q$_[1] \`");
|
||||
}
|
||||
|
||||
sub post_endpageref {
|
||||
&post_text("'");
|
||||
}
|
||||
|
||||
1;
|
||||
Reference in New Issue
Block a user