NCEPLIBS-sp 2.4.0
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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... | |
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 |
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. | |
KMAX | number | |
[out] | WAVE | wave field if IDIR>0 where MX=(MAXWV+1)*((IROMB+1)*MAXWV+2) |
[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). |