S 0 IndexS 1 Introduction and General InformationQ whatisfftw 1.1 What is FFTW?Q whereisfftw 1.2 How do I obtain FFTW?Q isfftwfree 1.3 Is FFTW free software?Q nonfree 1.4 What is this about non-free licenses?S 2 Installing FFTWQ systems 2.1 Which systems does FFTW run on?Q runOnDOS 2.2 Does FFTW run on DOS/Windows?Q compilerCrashes 2.3 My compiler has trouble with FFTW.Q solarisSucks 2.4 FFTW does not compile on Solaris, complaining about \courier{const\}.Q languages 2.5 Which language is FFTW written in?Q fortran 2.6 Can I call FFTW from FORTRAN?Q cplusplus 2.7 Can I call FFTW from C++?Q whynotfortran 2.8 Why isn't FFTW written in FORTRAN/C++?Q singleprec 2.9 How do I compile FFTW to run in single precision?S 3 Using FFTWQ slow 3.1 FFTW seems really slow.Q slows 3.2 FFTW slows down after repeated calls.Q segfault 3.3 An FFTW routine is crashing when I call it.Q fortran64 3.4 My Fortran program crashes when calling FFTW.Q conventions 3.5 FFTW gives results different from my old FFT.Q inplace 3.6 Your in-place transform gives incorrect results.Q savePlans 3.7 Can I save FFTW's plans?Q whyscaled 3.8 Why does your inverse transform return a scaled result?Q centerorigin 3.9 How can I make FFTW put the origin (zero frequency) at the center of its output?Q imageaudio 3.10 How do I FFT an image/audio file in \italic{foobar\} format?Q linkfails 3.11 My program does not link (on Unix).Q nostack 3.12 My program crashes, complaining about stack space.S 4 Internals of FFTWQ howworks 4.1 How does FFTW work?Q whyfast 4.2 Why is FFTW so fast?Q wisdom 4.3 What is this \courier{wisdom\} thing?Q whywisdom 4.4 Why do you use \courier{wisdom\}? I just wanted to save a plan.S 5 Known bugsQ rfftwndbug 5.1 FFTW 1.1 crashes in rfftwnd on Linux.Q fftwmpibug 5.2 The MPI transforms in FFTW 1.2 give incorrect results/leak memory.Q testsingbug 5.3 The test programs in FFTW 1.2.1 fail when I change FFTW to use single precision.Q teststoobig 5.4 The test program in FFTW 1.2.1 fails for n > 46340.Q linuxthreads 5.5 The threaded code fails on Linux Redhat 5.0Q bigrfftwnd 5.6 FFTW 2.0's rfftwnd fails for rank > 1 transforms with a final dimension >= 65536.Q primebug 5.7 FFTW 2.0's complex transforms give the wrong results with prime factors 17 to 97.Q mpichbug 5.8 FFTW 2.1.1's MPI test programs crash with MPICH.Q aixthreadbug 5.9 FFTW 2.1.2's multi-threaded transforms don't work on AIX.Q bigprimebug 5.10 FFTW 2.1.2's complex transforms give incorrect results for large prime sizes.Q aixflags 5.11 FFTW 2.1.3 crashes on AIX