SPTRANF

The SPTRANF routine performs a spherical transform
           between spectral coefficients of scalar quantities
           and fields on a global cylindrical grid.
           The wave-space can be either Triangular or Rhomboidal.
           The grid-space can be either an equally-spaced grid
           (with or without pole points) or a Gaussian grid.
           The wave and grid fields may have general indexing,
           but each wave field is in sequential 'IBM order',
           i.e. with zonal wavenumber as the slower index.
           Transforms are done in latitude pairs for efficiency;
           Thus grid arrays for each hemisphere must be passed.
           If so requested, just a subset of the latitude pairs
           may be transformed in each invocation of the subprogram.
           The transforms are all multiprocessed over latitude except
           The transform from Fourier to spectral is multiprocessed
           over zonal wavenumber to ensure reproducibility.
           Transform several fields at a time to improve vectorization.
           Subprogram can be called from a multiprocessing environment.

USAGE:    CALL SPTRANF(IROMB,MAXWV,IDRT,IMAX,JMAX,KMAX,
                       IP,IS,JN,JS,KW,KG,JB,JE,JC,
                       WAVE,GRIDN,GRIDS,IDIR)

   Input arguments:
      IROMB    - INTEGER SPECTRAL DOMAIN SHAPE
                 (0 FOR TRIANGULAR, 1 FOR RHOMBOIDAL)
      MAXWV    - INTEGER SPECTRAL TRUNCATION
      IDRT     - INTEGER GRID IDENTIFIER
                 (IDRT=4 FOR GAUSSIAN GRID,
                  IDRT=0 FOR EQUALLY-SPACED GRID INCLUDING POLES,
                  IDRT=256 FOR EQUALLY-SPACED GRID EXCLUDING POLES)
      IMAX     - INTEGER EVEN NUMBER OF LONGITUDES.
      JMAX     - INTEGER NUMBER OF LATITUDES.
      KMAX     - INTEGER NUMBER OF FIELDS TO TRANSFORM.
      IP       - INTEGER LONGITUDE INDEX FOR THE PRIME MERIDIAN
      IS       - INTEGER SKIP NUMBER BETWEEN LONGITUDES
      JN       - INTEGER SKIP NUMBER BETWEEN N.H. LATITUDES FROM NORTH
      JS       - INTEGER SKIP NUMBER BETWEEN S.H. LATITUDES FROM SOUTH
      KW       - INTEGER SKIP NUMBER BETWEEN WAVE FIELDS
      KG       - INTEGER SKIP NUMBER BETWEEN GRID FIELDS
      JB       - INTEGER LATITUDE INDEX (FROM POLE) TO BEGIN TRANSFORM
      JE       - INTEGER LATITUDE INDEX (FROM POLE) TO END TRANSFORM
      JC       - INTEGER NUMBER OF CPUS OVER WHICH TO MULTIPROCESS
      WAVE     - REAL (*) WAVE FIELDS IF IDIR>0
      GRIDN    - REAL (*) N.H. GRID FIELDS (STARTING AT JB) IF IDIR<0
      GRIDS    - REAL (*) S.H. GRID FIELDS (STARTING AT JB) IF IDIR<0
      IDIR     - INTEGER TRANSFORM FLAG
                 (IDIR>0 FOR WAVE TO GRID, IDIR<0 FOR GRID TO WAVE)

   Output arguments:
      WAVE     - REAL (*) WAVE FIELDS IF IDIR<0
      GRIDN    - REAL (*) N.H. GRID FIELDS (STARTING AT JB) IF IDIR>0
      GRIDS    - REAL (*) S.H. GRID FIELDS (STARTING AT JB) IF IDIR>0

 


  
SPLIB.tar
  
Library contains routines to be
   be used for a variety of spectral transform functions. (Fortran90) 

   Date posted: 2/23/2007