NCEPLIBS-sp 2.4.0
sptezmd.f File Reference

Perform simple gradient spherical transforms. More...

Go to the source code of this file.

Functions/Subroutines

subroutine sptezmd (IROMB, MAXWV, IDRT, IMAX, JMAX, KMAX, WAVE, GRIDMN, GRIDX, GRIDY, IDIR)
 This subprogram performs spherical transforms between spectral coefficients of scalar fields and their means and gradients on a global cylindrical grid. More...
 

Detailed Description

Perform simple gradient spherical transforms.

Author
Iredell
Date
96-02-29

Definition in file sptezmd.f.

Function/Subroutine Documentation

◆ sptezmd()

subroutine sptezmd (   IROMB,
  MAXWV,
  IDRT,
  IMAX,
  JMAX,
  KMAX,
real, dimension((maxwv+1)*((iromb+1)*maxwv+2),kmax)  WAVE,
real, dimension(kmax)  GRIDMN,
real, dimension(imax,jmax,kmax)  GRIDX,
real, dimension(imax,jmax,kmax)  GRIDY,
  IDIR 
)

This subprogram performs spherical transforms between spectral coefficients of scalar fields and their means and gradients 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 fields are in sequential 'IBM ORDER'.

The grid fields are 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.
KMAXnumber
[out]WAVEwave field if IDIR>0 where MX=(MAXWV+1)*((IROMB+1)*MAXWV+2)
[out]GRIDMNglobal mean if IDIR<0
[out]GRIDXgrid x-gradients (E->W,N->S) if IDIR<0
[out]GRIDYgrid y-gradients (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 52 of file sptezmd.f.

References ncpus(), and sptrand().