NCEPLIBS-sp 2.4.0
sptez.f File Reference

Perform a simple scalar spherical transform. More...

Go to the source code of this file.

Functions/Subroutines

subroutine sptez (IROMB, MAXWV, IDRT, IMAX, JMAX, WAVE, GRID, IDIR)
 This subprogram performs a spherical transform between spectral coefficients of a scalar quantity and a field on a global cylindrical grid. More...
 

Detailed Description

Perform a simple scalar spherical transform.

Author
Iredell
Date
96-02-29

Definition in file sptez.f.

Function/Subroutine Documentation

◆ sptez()

subroutine sptez (   IROMB,
  MAXWV,
  IDRT,
  IMAX,
  JMAX,
real, dimension((maxwv+1)*((iromb+1)*maxwv+2))  WAVE,
real, dimension(imax,jmax)  GRID,
  IDIR 
)

This subprogram performs a spherical transform between spectral coefficients of a scalar quantity and a field 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 field 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
IROMBspectral domain shape (0 for triangular, 1 for rhomboidal)
MAXWVspectral truncation
IDRTgrid identifier
  • IDRT=4 for Gaussian grid,
  • IDRT=0 for equally-spaced grid including poles,
  • IDRT=256 for equally-spaced grid excluding poles
IMAXeven number of longitudes.
JMAXnumber of latitudes.
[out]WAVEwave field if IDIR>0 where MX=(MAXWV+1)*((IROMB+1)*MAXWV+2)/2
[out]GRIDgrid field (E->W,N->S) if IDIR<0
IDIRtransform flag (IDIR>0 for wave to grid, IDIR<0 for grid to wave).
Author
Iredell
Date
96-02-29

Definition at line 49 of file sptez.f.

References ncpus(), and sptranf().