SPTEZV

The SPTEZV routine performs a Spherical transform
           between spectral coefficients of divergence and curl
           and a vector field 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 field is in sequential 'IBM order'.
           The grid fiels is indexed East to West, then North to South.
           For more flexibility and efficiency, call SPTRAN.
           Subprogram can be called from a multiprocessing environment.

USAGE:    CALL SPTEZV(IROMB,MAXWV,IDRT,IMAX,JMAX,
                      WAVED,WAVEZ,GRIDU,GRIDV,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.
      WAVED    - REAL (2*MX) WAVE DIVERGENCE FIELD IF IDIR>0
                 WHERE MX=(MAXWV+1)*((IROMB+1)*MAXWV+2)/2
      WAVEZ    - REAL (2*MX) WAVE VORTICITY FIELD IF IDIR>0
                 WHERE MX=(MAXWV+1)*((IROMB+1)*MAXWV+2)/2
      GRIDU    - REAL (IMAX,JMAX) GRID U-WIND (E->W,N->S) IF IDIR<0
      GRIDV    - REAL (IMAX,JMAX) GRID V-WIND (E->W,N->S) IF IDIR<0
      IDIR     - INTEGER TRANSFORM FLAG
                 (IDIR>0 FOR WAVE TO GRID, IDIR<0 FOR GRID TO WAVE)

   Output arguments:
      WAVED    - REAL (2*MX) WAVE DIVERGENCE FIELD IF IDIR<0
                 WHERE MX=(MAXWV+1)*((IROMB+1)*MAXWV+2)/2
      WAVEZ    - REAL (2*MX) WAVE VORTICITY FIELD IF IDIR>0
                 WHERE MX=(MAXWV+1)*((IROMB+1)*MAXWV+2)/2
      GRIDU    - REAL (IMAX,JMAX) GRID U-WIND (E->W,N->S) IF IDIR>0
      GRIDV    - REAL (IMAX,JMAX) GRID V-WIND (E->W,N->S) IF IDIR>0
 
REMARKS:
        MINIMUM GRID DIMENSIONS FOR UNALIASED TRANSFORMS TO SPECTRAL:

    DIMENSION                    LINEAR              QUADRATIC
    -----------------------      ---------           -------------
    IMAX                         2*MAXWV+2           3*MAXWV/2*2+2
    JMAX (IDRT=4,IROMB=0)        1*MAXWV+1           3*MAXWV/2+1
    JMAX (IDRT=4,IROMB=1)        2*MAXWV+1           5*MAXWV/2+1
    JMAX (IDRT=0,IROMB=0)        2*MAXWV+3           3*MAXWV/2*2+3
    JMAX (IDRT=0,IROMB=1)        4*MAXWV+3           5*MAXWV/2*2+3
    JMAX (IDRT=256,IROMB=0)      2*MAXWV+1           3*MAXWV/2*2+1
    JMAX (IDRT=256,IROMB=1)      4*MAXWV+1           5*MAXWV/2*2+1
 
 


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

   Date posted: 2/23/2007