NCEPLIBS-w3emc 2.12.0
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w3ft11.f File Reference

Computes 2.5x2.5 s. More...

Go to the source code of this file.

Functions/Subroutines

subroutine w3ft11 (vln, gn, pln, eps, fl, work, trigs, rcos)
 Computes 2.5 x 2.5 s.
 

Detailed Description

Computes 2.5x2.5 s.

hemi. grid vector.

Author
Joe Sela
Date
1980-11-20

Definition in file w3ft11.f.

Function/Subroutine Documentation

◆ w3ft11()

subroutine w3ft11 ( complex, dimension( 32 , 31 )  vln,
real, dimension(145,37)  gn,
real, dimension( 32 , 31 )  pln,
real, dimension( 992 )  eps,
complex, dimension( 31 )  fl,
real, dimension(144)  work,
real, dimension(216)  trigs,
real, dimension(37)  rcos 
)

Computes 2.5 x 2.5 s.

hemi. grid of 145 x 37 points from spectral coefficients in a rhomboidal 30 resolution representing a vector field.

Program History Log:

Date Programmer Comment
1980-11-20 Joe Sela Initial.
1984-06-15 Ralph Jones Change to ibm vs fortran.
1989-01-25 Ralph Jones Change to microsoft fortran 4.10.
1990-06-12 Ralph Jones Change to sun fortran 1.3.
1991-03-30 Ralph Jones Convert to silicongraphics fortran.
1993-03-29 Ralph Jones Add save statement.
1993-07-22 Ralph Jones Change double precision to real for cray.
Parameters
[in]VLN992 complex coeff.
[in]PLN992 real space for legendre polynomials.
[in]EPS992 real space for coeffs. used in computing pln.
[in]FL31 complex space for fourier coeff.
[in]WORK144 real work space for subr. w3ft12()
[in]TRIGS216 precomputed trig funcs. used in w3ft12(), computed by w3fa13()
[in]RCOS37 reciprocal cosine latitudes of 2.5 x 2.5 grid must be computed before first call to w3ft11 using subr. w3fa13()
[out]GN(145,37) grid values. 5365 point grid is type 30 or 1e hex o.n. 84
Note
This subroutine was optimized to run in a small amount of memory, it is not optimized for speed, 70 percent of the time is used by subroutine w3fa12() computing the legendre polynomials. Since the legendre polynomials are constant they need to be computed only once in a program. by moving w3fa12() to the main program and computing pln as a (32,31,37) array and changing this subroutine to use pln as a three dimension array you can cut the running time 70 percent.
Author
Joe Sela
Date
1980-11-20

Definition at line 40 of file w3ft11.f.