FFTW-WISDOM(1)			     fftw			FFTW-WISDOM(1)

NAME
       fftwf-wisdom - create wisdom (pre-optimized FFTs)

SYNOPSIS
       fftwf-wisdom [OPTION]... [SIZE]...

DESCRIPTION
       fftwf-wisdom is a utility to generate FFTW wisdom files, which contain
       saved information about how to optimally compute (Fourier) transforms
       of various sizes.  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

       Programs using FFTW can be written to load wisdom from an arbitrary
       file, string, or other source.  Moreover, it is likely that many FFTW-
       using programs will load the system wisdom file, which is stored in
       /etc/fftw/wisdomf by default.  fftwf-wisdom can be used to create or
       add to such wisdom files.  In its most typical usage, the wisdom file
       can be created to pre-plan a canonical set of sizes (see below) via:

			    fftwf-wisdom -v -c -o wisdomf


       (this will take many hours, which can be limited by the -t option) and
       the output wisdomf file can then be copied (as root) to /etc/fftw/ or
       whatever.

       The fftwf-wisdom program normally writes the wisdom directly to
       standard output, but this can be changed via the -o option, as in the
       example above.

       If the system wisdom file /etc/fftw/wisdomf already exists, then
       fftwf-wisdom reads this existing wisdom (unless the -n option is
       specified) and outputs both the old wisdom and any newly created
       wisdom.	In this way, it can be used to add new transform sizes to the
       existing system wisdom (or other wisdom file, with the -w option).

SPECIFYING SIZES
       Although a canonical set of sizes to optimize is specified by the -c
       option, the user can also specify zero or more non-canonical transform
       sizes and types to optimize, via the SIZE arguments following the
       option flags.  Alternatively, the sizes to optimize can be read from
       standard input (whitespace-separated), if a SIZE argument of "-" is
       supplied.

       Sizes are specified by the syntax:

			<type><inplace><direction><geometry>


       <type> is either ´c´ (complex), ´r´ (real, r2c/c2r), or ´k´ (r2r, per-
       dimension kinds, specified in the geometry, below).

       <inplace> is either ´i´ (in place) or ´o´ (out of place).

       <direction> is either ´f´ (forward) or ´b´ (backward).  The <direction>
       should be omitted for ´k´ transforms, where it is specified via the
       geometry instead.

       <geometry> is the size and dimensionality of the transform, where
       different dimensions are separated by ´x´ (e.g. ´16x32´ for a two-
       dimensional 16 by 32 transform).	 In the case of ´k´ transforms, the
       size of each dimension is followed by a "type" string, which can be one
       of f/b/h/e00/e01/e10/e11/o00/o01/o10/o11 for
       R2HC/HC2R/DHT/REDFT00/.../RODFT11, respectively, as defined in the FFTW
       manual.

       For example, ´cif12x13x14´ is a three-dimensional 12 by 13 x 14 complex
       DFT operating in-place.	´rob65536´ is a one-dimensional size-65536
       out-of-place complex-to-real (backwards) transform operating on
       Hermitian-symmetry input.  ´ki10hx20e01´ is a two-dimensional 10 by 20
       r2r transform where the first dimension is a DHT and the second
       dimension is an REDFT01 (DCT-III).


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

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

       -v, --verbose
	      Verbose output.  (You can specify this multiple times, or supply
	      a numeric argument greater than 1, to increase the verbosity
	      level.)  Note that the verbose output will be mixed with the
	      wisdom output (making it impossible to import), unless you write
	      the wisdom to a file via the -o option.

       -c, --canonical
	      Optimize/pre-plan a canonical set of sizes: all powers of two
	      and ten up to 2^20 (1048576), including both real and complex,
	      forward and backwards, in-place and out-of-place transforms.
	      Also includes two- and three-dimensional transforms of equal-
	      size dimensions (e.g. 16x16x16).

       -t hours, --time-limit=hours
	      Stop after a time of hours (hours) has elapsed, outputting
	      accumulated wisdom.  (The problems are planned in increasing
	      order of size.)  Defaults to 0, indicating no time limit.

       -o file, --output-file=file
	      Send wisdom output to file rather than to standard output (the
	      default).

       -m, --measure; -e, --estimate; -x, --exhaustive
	      Normally, fftwf-wisdom creates plans in FFTW_PATIENT mode, but
	      with these options you can instead use FFTW_MEASURE,
	      FFTW_ESTIMATE, or FFTW_EXHAUSTIVE modes, respectively, as
	      described in more detail by the FFTW manual.

	      Note that wisdom is tagged with the planning patience level, and
	      a single file can mix different levels of wisdom (e.g. you can
	      mostly use the patient default, but plan a few sizes that you
	      especially care about in --exhaustive mode).

       -n, --no-system-wisdom
	      Do not import the system wisdom from /etc/fftw/wisdomf (which is
	      normally read by default).

       -w file, --wisdom-file=file
	      Import wisdom from file (in addition to the system wisdom,
	      unless -n is specified).	Multiple wisdom files can be read via
	      multiple -w options.  If file is "-", then read wisdom from
	      standard input.

       -T N, --threads=N
	      Plan with N threads.  This option is only present if FFTW was
	      configured with thread support.

BUGS
       Send bug reports to fftw@fftw.org.

AUTHORS
       Written by Steven G. Johnson and Matteo Frigo.

       Copyright (c) 2003, 2007-14 Matteo Frigo
       Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology

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

fftw				February, 2003			FFTW-WISDOM(1)