sptezd.f File Reference

Perform a simple gradient spherical transform. More...

Go to the source code of this file.

Functions/Subroutines
subroutine	sptezd (IROMB, MAXWV, IDRT, IMAX, JMAX, WAVE, GRIDMN, GRIDX, GRIDY, IDIR)
	This subprogram performs a spherical transform between spectral coefficients of a scalar field and its mean and gradient on a global cylindrical grid. More...

Detailed Description

Perform a simple gradient spherical transform.

Author

Iredell

Date

96-02-29

Definition in file sptezd.f.

Function/Subroutine Documentation

sptezd()

subroutine sptezd	(		IROMB,
			MAXWV,
			IDRT,
			IMAX,
			JMAX,
		real, dimension(*)	WAVE,
			GRIDMN,
		real, dimension(imax,jmax)	GRIDX,
		real, dimension(imax,jmax)	GRIDY,
			IDIR
	)

This subprogram performs a spherical transform between spectral coefficients of a scalar field and its mean and gradient 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.

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

Parameters

	IROMB	spectral domain shape (0 for triangular, 1 for rhomboidal)
	MAXWV	spectral truncation
	IDRT	grid identifier IDRT=4 for Gaussian grid IDRT=0 for equally-spaced grid including poles IDRT=256 for equally-spaced grid excluding poles
	IMAX	even number of longitudes.
	JMAX	number of latitudes.
[out]	WAVE	wave field if IDIR>0
[out]	GRIDMN	global mean if IDIR<0
[out]	GRIDX	grid x-gradients (E->W,N->S) if IDIR<0
[out]	GRIDY	grid y-gradients (E->W,N->S) if IDIR<0
	IDIR	transform flag (IDIR>0 for wave to grid, IDIR<0 for grid to wave).

Author

Iredell

Date

96-02-29

Definition at line 50 of file sptezd.f.

References ncpus(), and sptrand().