4.7.4 Wisdom Utilities

FFTW includes two standalone utility programs that deal with wisdom. We merely summarize them here, since they come with their own man pages for Unix and GNU systems (with HTML versions on our web site).

The first program is fftw-wisdom (or fftwf-wisdom in single precision, etcetera), which can be used to create a wisdom file containing plans for any of the transform sizes and types supported by FFTW. It is preferable to create wisdom directly from your executable (see Caveats in Using Wisdom), but this program is useful for creating global wisdom files for fftw_import_system_wisdom.

The second program is fftw-wisdom-to-conf, which takes a wisdom file as input and produces a configuration routine as output. The latter is a C subroutine that you can compile and 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. fftw-wisdom-to-conf produces a configuration routine that links to only those parts of FFTW needed by the saved plans in the wisdom, greatly reducing the size of statically linked executables (which should only attempt to create plans corresponding to those in the wisdom, however).