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cannam@127:In this section, we discuss how one can import/export FFTW wisdom cannam@127: (saved plans) to/from a Fortran program; we assume that the reader is cannam@127: already familiar with wisdom, as described in Words of Wisdom-Saving Plans. cannam@127:
cannam@127: cannam@127:The basic problem is that is difficult to (portably) pass files and
cannam@127: strings between Fortran and C, so we cannot provide a direct Fortran
cannam@127: equivalent to the fftw_export_wisdom_to_file, etcetera,
cannam@127: functions. Fortran interfaces are provided for the functions
cannam@127: that do not take file/string arguments, however:
cannam@127: dfftw_import_system_wisdom, dfftw_import_wisdom,
cannam@127: dfftw_export_wisdom, and dfftw_forget_wisdom.
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So, for example, to import the system-wide wisdom, you would do: cannam@127:
cannam@127:integer isuccess cannam@127: call dfftw_import_system_wisdom(isuccess) cannam@127:
As usual, the C return value is turned into a first parameter;
cannam@127: isuccess is non-zero on success and zero on failure (e.g. if
cannam@127: there is no system wisdom installed).
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If you want to import/export wisdom from/to an arbitrary file or
cannam@127: elsewhere, you can employ the generic dfftw_import_wisdom and
cannam@127: dfftw_export_wisdom functions, for which you must supply a
cannam@127: subroutine to read/write one character at a time. The FFTW package
cannam@127: contains an example file doc/f77_wisdom.f demonstrating how to
cannam@127: implement import_wisdom_from_file and
cannam@127: export_wisdom_to_file subroutines in this way. (These routines
cannam@127: cannot be compiled into the FFTW library itself, lest all FFTW-using
cannam@127: programs be required to link with the Fortran I/O library.)
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