SPTRUNGV

The SPTRUNGV routine spectrally truncates vectors fields
             on a global cylindrical grid, returning the fields
             to specified sets of station points on the globe.
             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 grid and point fields may have general indexing.
             The transforms are all multiprocessed.
             Transform several fields at a time to improve vectorization.
             Subprogram can be called from a multiprocessing environment.

USAGE:    CALL SPTRUNGV(IROMB,MAXWV,IDRTI,IMAXI,JMAXI,KMAX,NMAX,
                        IPRIME,ISKIPI,JSKIPI,KSKIPI,KGSKIP,
                        NRSKIP,NGSKIP,JCPU,RLAT,RLON,GRIDUI,GRIDVI,
                        LUV,UP,VP,LDZ,DP,ZP,LPS,PP,SP)
   Input arguments:
      IROMB    - INTEGER SPECTRAL DOMAIN SHAPE
                 (0 FOR TRIANGULAR, 1 FOR RHOMBOIDAL)
      MAXWV    - INTEGER SPECTRAL TRUNCATION
      IDRTI    - INTEGER INPUT GRID IDENTIFIER
                 (IDRTI=4 FOR GAUSSIAN GRID,
                  IDRTI=0 FOR EQUALLY-SPACED GRID INCLUDING POLES,
                  IDRTI=256 FOR EQUALLY-SPACED GRID EXCLUDING POLES)
      IMAXI    - INTEGER EVEN NUMBER OF INPUT LONGITUDES.
      JMAXI    - INTEGER NUMBER OF INPUT LATITUDES.
      KMAX     - INTEGER NUMBER OF FIELDS TO TRANSFORM.
      NMAX     - INTEGER NUMBER OF STATION POINTS TO RETURN
      IPRIME   - INTEGER INPUT LONGITUDE INDEX FOR THE PRIME MERIDIAN.
                 (DEFAULTS TO 1 IF IPRIME=0)
                 (OUTPUT LONGITUDE INDEX FOR PRIME MERIDIAN ASSUMED 1.)
      ISKIPI   - INTEGER SKIP NUMBER BETWEEN INPUT LONGITUDES
                 (DEFAULTS TO 1 IF ISKIPI=0)
      JSKIPI   - INTEGER SKIP NUMBER BETWEEN INPUT LATITUDES FROM SOUTH
                 (DEFAULTS TO -IMAXI IF JSKIPI=0)
      KSKIPI   - INTEGER SKIP NUMBER BETWEEN INPUT GRID FIELDS
                 (DEFAULTS TO IMAXI*JMAXI IF KSKIPI=0)
      KGSKIP   - INTEGER SKIP NUMBER BETWEEN STATION POINT SETS
                 (DEFAULTS TO NMAX IF KGSKIP=0)
      NRSKIP   - INTEGER SKIP NUMBER BETWEEN STATION LATS AND LONS
                 (DEFAULTS TO 1 IF NRSKIP=0)
      NGSKIP   - INTEGER SKIP NUMBER BETWEEN STATION POINTS
                 (DEFAULTS TO 1 IF NGSKIP=0)
      RLAT     - REAL (*) STATION LATITUDES IN DEGREES
      RLON     - REAL (*) STATION LONGITUDES IN DEGREES
      JCPU     - INTEGER NUMBER OF CPUS OVER WHICH TO MULTIPROCESS
                 (DEFAULTS TO ENVIRONMENT NCPUS IF JCPU=0)
      GRIDUI   - REAL (*) INPUT GRID U-WINDS
      GRIDVI   - REAL (*) INPUT GRID V-WINDS
      LUV      - LOGICAL FLAG WHETHER TO RETURN WINDS
      LDZ      - LOGICAL FLAG WHETHER TO RETURN DIVERGENCE AND VORTICITY
      LPS      - LOGICAL FLAG WHETHER TO RETURN POTENTIAL AND STREAMFCN

   Output arguments:
      UP       - REAL (*) STATION U-WINDS IF LUV
      VP       - REAL (*) STATION V-WINDS IF LUV
      DP       - REAL (*) STATION DIVERGENCES IF LDZ
      ZP       - REAL (*) STATION VORTICITIES IF LDZ
      PP       - REAL (*) STATION POTENTIALS IF LPS
      SP       - REAL (*) STATION STREAMFCNS IF LPS
 
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