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fftw-wisdom-to-conf(1)               fftw               fftw-wisdom-to-conf(1)


       fftw-wisdom-to-conf - generate FFTW wisdom (pre-planned transforms)


       fftw-wisdom-to-conf [< INPUT] [> OUTPUT]


       fftw-wisdom-to-conf  is  a utility to generate C configuration routines
       from FFTW wisdom files, where  the  latter  contain  saved  information
       about  how  to optimally compute (Fourier) transforms of various sizes.
       A configuration routine is a C subroutine that you link into your  pro-
       gram,  replacing  a  routine of the same name in the FFTW library, that
       determines which parts of FFTW are callable by your program.

       The reason to do this is that, if you only need transforms of a limited
       set of sizes and types, and if you are statically linking your program,
       then using a configuration file generated from wisdom for  those  types
       can  substantially  reduce  the  size  of your executable.  (Otherwise,
       because of FFTW's dynamic nature, all of FFTW's transform code must  be
       linked into any program using FFTW.)

       FFTW is a free library to compute discrete Fourier transforms in one or
       more dimensions, for arbitrary sizes, and  of  both  real  and  complex
       data,  among other related operations.  More information on FFTW can be
       found at the FFTW home page:

       fftw-wisdom-to-conf reads wisdom from standard  input  and  writes  the
       configuration  to  standard output.  It can easily be combined with the
       fftw-wisdom tool, for example:

       fftw-wisdom -n cof1024 cob1024 -o wisdom
       fftw-wisdom-to-conf < wisdom > conf.c

       will create a configuration "conf.c" containing  only  those  parts  of
       FFTW  needed  for  the optimized complex forwards and backwards out-of-
       place transforms of size 1024 (also saving the wisdom itself  in  "wis-

       Alternatively,  you  can run your actual program, export wisdom for all
       plans that were created (ideally  in  FFTW_PATIENT  or  FFTW_EXHAUSTIVE
       mode), use this as input for fftw-wisdom-to-conf, and then re-link your
       program with the resulting configuration routine.

       Note that the configuration routine does not contain the  wisdom,  only
       the  routines necessary to implement the wisdom, so your program should
       also import the wisdom in  order  to  benefit  from  the  pre-optimized


       -h, --help
              Display help on the command-line options and usage.

       -V, --version
              Print the version number and copyright information.


       Send bug reports to


       Written by Steven G. Johnson and Matteo Frigo.

       Copyright (c) 2003, 2006 Matteo Frigo
       Copyright (c) 2003, 2006 Massachusetts Institute of Technology



fftw                            February, 2003          fftw-wisdom-to-conf(1)

fftw 3.1.2 - Generated Thu Jun 26 16:23:08 CDT 2008
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