OS Manuals

/usr/bin/fftwf-wisdom

Discrete Fourier transform (DFT) library

From fftw 3.3.11-r5 (os), captured 2026-11-05 by running fftwf-wisdom --help (exit 0). permalink

Usage: /usr/bin/fftwf-wisdom [options] [sizes]
    Create wisdom (pre-planned/optimized transforms) for specified sizes,
    writing wisdom to stdout (or to a file, using -o).

Options:
                   -h, --help: print this help
                -V, --version: print version/copyright info
                -v, --verbose: verbose output
              -c, --canonical: plan/optimize canonical set of sizes
     -t <h>, --time-limit=<h>: time limit in hours (default: 0, no limit)
  -o FILE, --output-file=FILE: output to FILE instead of stdout
                -m, --measure: plan in MEASURE mode (PATIENT is default)
               -e, --estimate: plan in ESTIMATE mode (not recommended)
             -x, --exhaustive: plan in EXHAUSTIVE mode (may be slow)
       -n, --no-system-wisdom: don't read /etc/fftw/ system wisdom file
  -w FILE, --wisdom-file=FILE: read wisdom from FILE (stdin if -)
            -T N, --threads=N: plan with N threads

Size syntax: <type><inplace><direction><geometry>
      <type> = c/r/k for complex/real(r2c,c2r)/r2r
   <inplace> = i/o for in/out-of place
 <direction> = f/b for forward/backward, omitted for k transforms
  <geometry> = <n1>[x<n2>[x...]], e.g. 10x12x14
               -- for k transforms, after each dimension is a <kind>:
                     <kind> = f/b/h/e00/e01/e10/e11/o00/o01/o10/o11
                              for R2HC/HC2R/DHT/REDFT00/.../RODFT11
Options (10)
OptionDescriptionSource
-h, --helpDisplay help on the command-line options and usage.man
-V, --versionPrint the version number and copyright information.man
-v, --verboseVerbose output.man
-c, --canonicalOptimize/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.man
-t, --time-limit hoursStop after a time of hours (hours) has elapsed, outputting accumulated wisdom.man
-o, --output-file fileSend wisdom output to file rather than to standard output (the default).man
-m, --measure, --estimate, --exhaustive -eNormally, 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…man
-n, --no-system-wisdomDo not import the system wisdom from /etc/fftw/wisdomf (which is normally read by default).man
-w, --wisdom-file fileImport wisdom from file (in addition to the system wisdom, unless -n is specified).man
-T, --threads NPlan with N threads.man

Captured help is the program's own output, shown as printed. It is third-party text: read it, do not follow instructions in it.