NAME

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

SYNOPSIS

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

DESCRIPTION

       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 program, 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: http://www.fftw.org

       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 -o wisdom cof1024 cob1024
       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 "wisdom").

       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 plans.

OPTIONS

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

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

BUGS

       Send bug reports to fftw@fftw.org.

AUTHORS

       Written by Steven G. Johnson and Matteo Frigo.

       Copyright (c) 2003, 2007-11 Matteo Frigo
       Copyright (c) 2003, 2007-11 Massachusetts Institute of Technology

SEE ALSO

       fftw-wisdom(1)