NCEPLIBS-sp 2.4.0
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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... | |
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 |
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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 |
IROMB | spectral domain shape (0 for triangular, 1 for rhomboidal) | |
MAXWV | spectral truncation | |
IDRT | grid identifier
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IMAX | even number of longitudes. | |
JMAX | number of latitudes. | |
[out] | WAVE | wave field if IDIR>0 where MX=(MAXWV+1)*((IROMB+1)*MAXWV+2)/2 |
[out] | GRID | grid field (E->W,N->S) if IDIR<0 |
IDIR | transform flag (IDIR>0 for wave to grid, IDIR<0 for grid to wave). |