sptranfv.f File Reference

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Functions/Subroutines
subroutine	sptranfv (IROMB, MAXWV, IDRT, IMAX, JMAX, KMAX, IP, IS, JN, JS, KW, KG, JB, JE, JC, WAVED, WAVEZ, GRIDUN, GRIDUS, GRIDVN, GRIDVS, IDIR)
	THIS SUBPROGRAM PERFORMS A SPHERICAL TRANSFORM BETWEEN SPECTRAL COEFFICIENTS OF DIVERGENCES AND CURLS AND VECTOR FIELDS ON A GLOBAL CYLINDRICAL GRID. More...

Detailed Description

Perform a vector spherical transform

Author

IREDELL

Date

96-02-29

Definition in file sptranfv.f.

Function/Subroutine Documentation

sptranfv()

subroutine sptranfv	(		IROMB,
			MAXWV,
			IDRT,
			IMAX,
			JMAX,
			KMAX,
			IP,
			IS,
			JN,
			JS,
			KW,
			KG,
			JB,
			JE,
			JC,
		real, dimension(*)	WAVED,
		real, dimension(*)	WAVEZ,
		real, dimension(*)	GRIDUN,
		real, dimension(*)	GRIDUS,
		real, dimension(*)	GRIDVN,
		real, dimension(*)	GRIDVS,
			IDIR
	)

THIS SUBPROGRAM PERFORMS A SPHERICAL TRANSFORM BETWEEN SPECTRAL COEFFICIENTS OF DIVERGENCES AND CURLS AND VECTOR 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.

PROGRAM HISTORY LOG:

• 96-02-29 IREDELL
• 1998-12-15 IREDELL GENERIC FFT USED, OPENMP DIRECTIVES INSERTED
• 2013-01-16 IREDELL & MIRVIS FIXING AFFT NEGATIVE SHARING EFFECT DURING OMP LOOPS BY CREATING TMP AFFT COPY (AFFT_TMP) TO BE PRIVATE DURING OMP LOOP THREADING

Parameters

	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
[out]	WAVED	- REAL (*) WAVE DIVERGENCE FIELDS IF IDIR>0 [WAVED=(D(GRIDU)/DLAM+D(CLAT*GRIDV)/DPHI)/(CLAT*RERTH)]
[out]	WAVEZ	- REAL (*) WAVE VORTICITY FIELDS IF IDIR>0 [WAVEZ=(D(GRIDV)/DLAM-D(CLAT*GRIDU)/DPHI)/(CLAT*RERTH)]
[out]	GRIDUN	- REAL (*) N.H. GRID U-WINDS (STARTING AT JB) IF IDIR<0
[out]	GRIDUS	- REAL (*) S.H. GRID U-WINDS (STARTING AT JB) IF IDIR<0
[out]	GRIDVN	- REAL (*) N.H. GRID V-WINDS (STARTING AT JB) IF IDIR<0
[out]	GRIDVS	- REAL (*) S.H. GRID V-WINDS (STARTING AT JB) IF IDIR<0
	IDIR	- INTEGER TRANSFORM FLAG (IDIR>0 FOR WAVE TO GRID, IDIR<0 FOR GRID TO WAVE)

SUBPROGRAMS CALLED:

• SPTRANF0 SPTRANF SPECTRAL INITIALIZATION
• SPTRANF1 SPTRANF SPECTRAL TRANSFORM
• SPDZ2UV COMPUTE WINDS FROM DIVERGENCE AND VORTICITY
• SPUV2DZ COMPUTE DIVERGENCE AND VORTICITY FROM WINDS

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 81 of file sptranfv.f.