All programs using FFTW’s MPI support should include its header file:
Note that this header file includes the serial-FFTW
header file, and also the
mpi.h header file for MPI, so you
need not include those files separately.
You must also link to both the FFTW MPI library and to the
serial FFTW library. On Unix, this means adding
-lfftw3 -lm at the end of the link command.
Different precisions are handled as in the serial interface:
See Precision. That is, ‘fftw_’ functions become
fftwf_ (in single precision) etcetera, and the libraries become
-lfftw3f_mpi -lfftw3f -lm etcetera on Unix. Long-double
precision is supported in MPI, but quad precision (‘fftwq_’) is
not due to the lack of MPI support for this type.