SPTRUN
The SPTRUN routine spectrally truncates scalar fields
on a global cylindrical grid, returning the fields
to a possibly different global cylindrical grid.
The wave-space can be either Triangular or Rhomboidal.
either grid-space can be either an equally-spaced grid
(with or without pole points) or a Gaussian grid.
The grid 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 SPTRUN(IROMB,MAXWV,IDRTI,IMAXI,JMAXI,IDRTO,IMAXO,JMAXO,
KMAX,IPRIME,ISKIPI,JSKIPI,KSKIPI,
ISKIPO,JSKIPO,KSKIPO,JCPU,GRIDI,GRIDO)
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.
IDRTO - INTEGER OUTPUT GRID IDENTIFIER
(IDRTO=4 FOR GAUSSIAN GRID,
IDRTO=0 FOR EQUALLY-SPACED GRID INCLUDING POLES,
IDRTO=256 FOR EQUALLY-SPACED GRID EXCLUDING POLES)
IMAXO - INTEGER EVEN NUMBER OF OUTPUT LONGITUDES.
JMAXO - INTEGER NUMBER OF OUTPUT LATITUDES.
KMAX - INTEGER NUMBER OF FIELDS TO TRANSFORM.
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)
ISKIPO - INTEGER SKIP NUMBER BETWEEN OUTPUT LONGITUDES
(DEFAULTS TO 1 IF ISKIPO=0)
JSKIPO - INTEGER SKIP NUMBER BETWEEN OUTPUT LATITUDES FROM SOUTH
(DEFAULTS TO -IMAXO IF JSKIPO=0)
KSKIPO - INTEGER SKIP NUMBER BETWEEN OUTPUT GRID FIELDS
(DEFAULTS TO IMAXO*JMAXO IF KSKIPO=0)
JCPU - INTEGER NUMBER OF CPUS OVER WHICH TO MULTIPROCESS
(DEFAULTS TO ENVIRONMENT NCPUS IF JCPU=0)
GRIDI - REAL (*) INPUT GRID FIELDS
Output arguments:
GRIDO - REAL (*) OUTPUT GRID FIELDS
(MAY OVERLAY INPUT FIELDS IF GRID SHAPE IS APPROPRIATE)
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 |