1FFTW-WISDOM-TO-CONF(1)               fftw               FFTW-WISDOM-TO-CONF(1)
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NAME

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

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

12       fftw-wisdom-to-conf  is  a utility to generate C configuration routines
13       from FFTW wisdom files, where  the  latter  contain  saved  information
14       about  how  to optimally compute (Fourier) transforms of various sizes.
15       A configuration routine is a C subroutine that you link into your  pro‐
16       gram,  replacing  a  routine of the same name in the FFTW library, that
17       determines which parts of FFTW are callable by your program.
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19       The reason to do this is that, if you only need transforms of a limited
20       set of sizes and types, and if you are statically linking your program,
21       then using a configuration file generated from wisdom for  those  types
22       can  substantially  reduce  the  size  of your executable.  (Otherwise,
23       because of FFTW's dynamic nature, all of FFTW's transform code must  be
24       linked into any program using FFTW.)
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26       FFTW is a free library to compute discrete Fourier transforms in one or
27       more dimensions, for arbitrary sizes, and  of  both  real  and  complex
28       data,  among other related operations.  More information on FFTW can be
29       found at the FFTW home page: http://www.fftw.org
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31       fftw-wisdom-to-conf reads wisdom from standard  input  and  writes  the
32       configuration  to  standard output.  It can easily be combined with the
33       fftw-wisdom tool, for example:
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35       fftw-wisdom -n cof1024 cob1024 -o wisdom
36       fftw-wisdom-to-conf < wisdom > conf.c
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38       will create a configuration "conf.c" containing  only  those  parts  of
39       FFTW  needed  for  the optimized complex forwards and backwards out-of-
40       place transforms of size 1024 (also saving the wisdom itself  in  "wis‐
41       dom").
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43       Alternatively,  you  can run your actual program, export wisdom for all
44       plans that were created (ideally  in  FFTW_PATIENT  or  FFTW_EXHAUSTIVE
45       mode), use this as input for fftw-wisdom-to-conf, and then re-link your
46       program with the resulting configuration routine.
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48       Note that the configuration routine does not contain the  wisdom,  only
49       the  routines necessary to implement the wisdom, so your program should
50       also import the wisdom in  order  to  benefit  from  the  pre-optimized
51       plans.
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OPTIONS

54       -h, --help
55              Display help on the command-line options and usage.
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57       -V, --version
58              Print the version number and copyright information.
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BUGS

61       Send bug reports to fftw@fftw.org.
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AUTHORS

64       Written by Steven G. Johnson and Matteo Frigo.
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66       Copyright (c) 2003, 2007-8 Matteo Frigo
67       Copyright (c) 2003, 2007-8 Massachusetts Institute of Technology
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SEE ALSO

70       fftw-wisdom(1)
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74fftw                            February, 2003          FFTW-WISDOM-TO-CONF(1)
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