fft_mc_setup

subroutine fft_mc_setup( pixelization, nmmax)

Purpose:

Precomputes the FFT plans for use by the harmonic transforms. It should be called before any call to the harmonic transforms. The precomputed plans are stored and used by all following transforms until the fft_mc_clean routine is revoked. As the FFT plans depend on the maps to be analyzed they need to be recomputed for each different case. Note that every subsequent call to fft_mc_setup needs to be preceded by a call to fft_mc_clean. The routine is useful whenever multiple transforms of the same type are to be performed and helps to save some run time. It has to be called by all procs.
If no fft_mc_setup call is performed prior to calling one of the harmonic transform routines, the latter will compute the plans internaly on a transform-by-transform basis.

The routine can be used for any allowed choice of the FFT package.

Parameter description:

input:

pixelization-- [pixeltype], an S2HAT structure containing the info about the pixelization;

nmmax-- [integer(4b)], a maximal considered value of m.