Mercurial > hg > sv-dependency-builds

annotate src/fftw-3.3.5/doc/FAQ/fftw-faq.html/index.html @ 83:ae30d91d2ffe

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Replace these with versions built using an older toolset (so as to avoid ABI compatibilities when linking on Ubuntu 14.04 for packaging purposes)
author Chris Cannam
date Fri, 07 Feb 2020 11:51:13 +0000
parents 2cd0e3b3e1fd
children
rev   line source
Chris@42 1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
Chris@42 2 <html>
Chris@42 3 <head><title>
Chris@42 4 FFTW Frequently Asked Questions with Answers
Chris@42 5 </title>
Chris@42 6 <link rev="made" href="mailto:fftw@fftw.org">
Chris@42 7 <link rel="Contents" href="index.html">
Chris@42 8 <link rel="Start" href="index.html">
Chris@42 9 <META name="description"
Chris@42 10 content="Frequently asked questions and answers (FAQ) for FFTW.">
Chris@42 11 <link rel="Bookmark" title="FFTW FAQ" href="index.html">
Chris@42 12 <LINK rel="Bookmark" title="FFTW Home Page"
Chris@42 13 href="http://www.fftw.org">
Chris@42 14 <LINK rel="Bookmark" title="FFTW Manual"
Chris@42 15 href="http://www.fftw.org/doc/">
Chris@42 16 </head><body text="#000000" bgcolor="#FFFFFF"><h1>
Chris@42 17 FFTW Frequently Asked Questions with Answers
Chris@42 18 </h1>
Chris@42 19 This is the list of Frequently Asked Questions about FFTW, a
Chris@42 20 collection of fast C routines for computing the Discrete Fourier
Chris@42 21 Transform in one or more dimensions.
Chris@42 22 <h1>
Chris@42 23 Index
Chris@42 24 </h1>
Chris@42 25
Chris@42 26 <ul>
Chris@42 27 <li><b><font size="+2"><a href="section1.html" rel=subdocument>Section 1. Introduction and General Information</a></font></b>
Chris@42 28 <li><a href="section1.html#whatisfftw" rel=subdocument>Q1.1. What is FFTW?</a>
Chris@42 29 <li><a href="section1.html#whereisfftw" rel=subdocument>Q1.2. How do I obtain FFTW?</a>
Chris@42 30 <li><a href="section1.html#isfftwfree" rel=subdocument>Q1.3. Is FFTW free software?</a>
Chris@42 31 <li><a href="section1.html#nonfree" rel=subdocument>Q1.4. What is this about non-free licenses?</a>
Chris@42 32 <li><a href="section1.html#west" rel=subdocument>Q1.5. In the West? I thought MIT was in the East?</a>
Chris@42 33 <br><br><li><b><font size="+2"><a href="section2.html" rel=subdocument>Section 2. Installing FFTW</a></font></b>
Chris@42 34 <li><a href="section2.html#systems" rel=subdocument>Q2.1. Which systems does FFTW run on?</a>
Chris@42 35 <li><a href="section2.html#runOnWindows" rel=subdocument>Q2.2. Does FFTW run on Windows?</a>
Chris@42 36 <li><a href="section2.html#compilerCrashes" rel=subdocument>Q2.3. My compiler has trouble with FFTW.</a>
Chris@42 37 <li><a href="section2.html#solarisSucks" rel=subdocument>Q2.4. FFTW does not compile on Solaris, complaining about
Chris@42 38 <code>const</code>.</a>
Chris@42 39 <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>
Chris@42 40 <li><a href="section2.html#fma" rel=subdocument>Q2.6. What's the difference between the fma and the non-fma
Chris@42 41 versions?</a>
Chris@42 42 <li><a href="section2.html#languages" rel=subdocument>Q2.7. Which language is FFTW written in?</a>
Chris@42 43 <li><a href="section2.html#fortran" rel=subdocument>Q2.8. Can I call FFTW from Fortran?</a>
Chris@42 44 <li><a href="section2.html#cplusplus" rel=subdocument>Q2.9. Can I call FFTW from C++?</a>
Chris@42 45 <li><a href="section2.html#whynotfortran" rel=subdocument>Q2.10. Why isn't FFTW written in Fortran/C++?</a>
Chris@42 46 <li><a href="section2.html#singleprec" rel=subdocument>Q2.11. How do I compile FFTW to run in single precision?</a>
Chris@42 47 <li><a href="section2.html#64bitk7" rel=subdocument>Q2.12. --enable-k7 does not work on x86-64</a>
Chris@42 48 <br><br><li><b><font size="+2"><a href="section3.html" rel=subdocument>Section 3. Using FFTW</a></font></b>
Chris@42 49 <li><a href="section3.html#fftw2to3" rel=subdocument>Q3.1. Why not support the FFTW 2 interface in FFTW
Chris@42 50 3?</a>
Chris@42 51 <li><a href="section3.html#planperarray" rel=subdocument>Q3.2. Why do FFTW 3 plans encapsulate the input/output arrays and not just
Chris@42 52 the algorithm?</a>
Chris@42 53 <li><a href="section3.html#slow" rel=subdocument>Q3.3. FFTW seems really slow.</a>
Chris@42 54 <li><a href="section3.html#slows" rel=subdocument>Q3.4. FFTW slows down after repeated calls.</a>
Chris@42 55 <li><a href="section3.html#segfault" rel=subdocument>Q3.5. An FFTW routine is crashing when I call it.</a>
Chris@42 56 <li><a href="section3.html#fortran64" rel=subdocument>Q3.6. My Fortran program crashes when calling FFTW.</a>
Chris@42 57 <li><a href="section3.html#conventions" rel=subdocument>Q3.7. FFTW gives results different from my old
Chris@42 58 FFT.</a>
Chris@42 59 <li><a href="section3.html#nondeterministic" rel=subdocument>Q3.8. FFTW gives different results between runs</a>
Chris@42 60 <li><a href="section3.html#savePlans" rel=subdocument>Q3.9. Can I save FFTW's plans?</a>
Chris@42 61 <li><a href="section3.html#whyscaled" rel=subdocument>Q3.10. Why does your inverse transform return a scaled
Chris@42 62 result?</a>
Chris@42 63 <li><a href="section3.html#centerorigin" rel=subdocument>Q3.11. How can I make FFTW put the origin (zero frequency) at the center of
Chris@42 64 its output?</a>
Chris@42 65 <li><a href="section3.html#imageaudio" rel=subdocument>Q3.12. How do I FFT an image/audio file in <i>foobar</i> format?</a>
Chris@42 66 <li><a href="section3.html#linkfails" rel=subdocument>Q3.13. My program does not link (on Unix).</a>
Chris@42 67 <li><a href="section3.html#linkheader" rel=subdocument>Q3.14. I included your header, but linking still
Chris@42 68 fails.</a>
Chris@42 69 <li><a href="section3.html#nostack" rel=subdocument>Q3.15. My program crashes, complaining about stack
Chris@42 70 space.</a>
Chris@42 71 <li><a href="section3.html#leaks" rel=subdocument>Q3.16. FFTW seems to have a memory leak.</a>
Chris@42 72 <li><a href="section3.html#allzero" rel=subdocument>Q3.17. The output of FFTW's transform is all zeros.</a>
Chris@42 73 <li><a href="section3.html#vbetalia" rel=subdocument>Q3.18. How do I call FFTW from the Microsoft language du
Chris@42 74 jour?</a>
Chris@42 75 <li><a href="section3.html#pruned" rel=subdocument>Q3.19. Can I compute only a subset of the DFT outputs?</a>
Chris@42 76 <li><a href="section3.html#transpose" rel=subdocument>Q3.20. Can I use FFTW's routines for in-place and out-of-place matrix
Chris@42 77 transposition?</a>
Chris@42 78 <br><br><li><b><font size="+2"><a href="section4.html" rel=subdocument>Section 4. Internals of FFTW</a></font></b>
Chris@42 79 <li><a href="section4.html#howworks" rel=subdocument>Q4.1. How does FFTW work?</a>
Chris@42 80 <li><a href="section4.html#whyfast" rel=subdocument>Q4.2. Why is FFTW so fast?</a>
Chris@42 81 <br><br><li><b><font size="+2"><a href="section5.html" rel=subdocument>Section 5. Known bugs</a></font></b>
Chris@42 82 <li><a href="section5.html#rfftwndbug" rel=subdocument>Q5.1. FFTW 1.1 crashes in rfftwnd on Linux.</a>
Chris@42 83 <li><a href="section5.html#fftwmpibug" rel=subdocument>Q5.2. The MPI transforms in FFTW 1.2 give incorrect results/leak
Chris@42 84 memory.</a>
Chris@42 85 <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
Chris@42 86 precision.</a>
Chris@42 87 <li><a href="section5.html#teststoobig" rel=subdocument>Q5.4. The test program in FFTW 1.2.1 fails for n &gt;
Chris@42 88 46340.</a>
Chris@42 89 <li><a href="section5.html#linuxthreads" rel=subdocument>Q5.5. The threaded code fails on Linux Redhat 5.0</a>
Chris@42 90 <li><a href="section5.html#bigrfftwnd" rel=subdocument>Q5.6. FFTW 2.0's rfftwnd fails for rank &gt; 1 transforms with a final
Chris@42 91 dimension &gt;= 65536.</a>
Chris@42 92 <li><a href="section5.html#primebug" rel=subdocument>Q5.7. FFTW 2.0's complex transforms give the wrong results with prime
Chris@42 93 factors 17 to 97.</a>
Chris@42 94 <li><a href="section5.html#mpichbug" rel=subdocument>Q5.8. FFTW 2.1.1's MPI test programs crash with
Chris@42 95 MPICH.</a>
Chris@42 96 <li><a href="section5.html#aixthreadbug" rel=subdocument>Q5.9. FFTW 2.1.2's multi-threaded transforms don't work on
Chris@42 97 AIX.</a>
Chris@42 98 <li><a href="section5.html#bigprimebug" rel=subdocument>Q5.10. FFTW 2.1.2's complex transforms give incorrect results for large prime
Chris@42 99 sizes.</a>
Chris@42 100 <li><a href="section5.html#solaristhreadbug" rel=subdocument>Q5.11. FFTW 2.1.3's multi-threaded transforms don't give any speedup on
Chris@42 101 Solaris.</a>
Chris@42 102 <li><a href="section5.html#aixflags" rel=subdocument>Q5.12. FFTW 2.1.3 crashes on AIX.</a>
Chris@42 103 </ul><hr>
Chris@42 104 <address>
Chris@42 105 <A href="http://www.fftw.org">Matteo Frigo and Steven G. Johnson</A> / <A href="mailto:fftw@fftw.org">fftw@fftw.org</A>
Chris@42 106 - 30 July 2016
Chris@42 107 </address><br>
Chris@42 108 Extracted from FFTW Frequently Asked Questions with Answers,
Chris@42 109 Copyright &copy; 2016 Matteo Frigo and Massachusetts Institute of Technology.
Chris@42 110 </body></html>