sptrunl.f File Reference

Spectrally truncate to laplacian. More...

Go to the source code of this file.

Functions/Subroutines
subroutine	sptrunl (IROMB, MAXWV, IDRTI, IMAXI, JMAXI, IDRTO, IMAXO, JMAXO, KMAX, IPRIME, ISKIPI, JSKIPI, KSKIPI, ISKIPO, JSKIPO, KSKIPO, JCPU, IDIR, GRIDI, GRIDO)
	THIS SUBPROGRAM SPECTRALLY TRUNCATES SCALAR FIELDS ON A GLOBAL CYLINDRICAL GRID, RETURNING THEIR LAPLACIAN OR INVERSE TO A POSSIBLY DIFFERENT GLOBAL CYLINDRICAL GRID. More...

Detailed Description

Spectrally truncate to laplacian.

Author

IREDELL

Date

96-02-29

Definition in file sptrunl.f.

Function/Subroutine Documentation

sptrunl()

subroutine sptrunl	(		IROMB,
			MAXWV,
			IDRTI,
			IMAXI,
			JMAXI,
			IDRTO,
			IMAXO,
			JMAXO,
			KMAX,
			IPRIME,
			ISKIPI,
			JSKIPI,
			KSKIPI,
			ISKIPO,
			JSKIPO,
			KSKIPO,
			JCPU,
			IDIR,
		real, dimension(*)	GRIDI,
		real, dimension(*)	GRIDO
	)

THIS SUBPROGRAM SPECTRALLY TRUNCATES SCALAR FIELDS ON A GLOBAL CYLINDRICAL GRID, RETURNING THEIR LAPLACIAN OR INVERSE 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. OVER ZONAL WAVENUMBER TO ENSURE REPRODUCIBILITY. TRANSFORM SEVERAL FIELDS AT A TIME TO IMPROVE VECTORIZATION. SUBPROGRAM CAN BE CALLED FROM A MULTIPROCESSING ENVIRONMENT.

PROGRAM HISTORY LOG:

• 96-02-29 IREDELL
• 1998-12-15 IREDELL OPENMP DIRECTIVES INSERTED

Parameters

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)
IDIR	- INTEGER FLAG IDIR > 0 TO TAKE LAPLACIAN IDIR < 0 TO TAKE INVERSE LAPLACIAN
GRIDI	- REAL (*) INPUT GRID FIELDS
GRIDO	- REAL (*) OUTPUT GRID FIELDS (MAY OVERLAY INPUT FIELDS IF GRID SHAPE IS APPROPRIATE)

SUBPROGRAMS CALLED:

• SPWGET GET WAVE-SPACE CONSTANTS
• SPLAPLAC COMPUTE LAPLACIAN IN SPECTRAL SPACE
• SPTRAN PERFORM A SCALAR SPHERICAL TRANSFORM
• NCPUS GETS ENVIRONMENT NUMBER OF CPUS

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

Definition at line 78 of file sptrunl.f.

References ncpus(), splaplac(), sptran(), and spwget().