w3ft09.f File Reference

Computes 2.5x2.5 n. More...

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Functions/Subroutines
subroutine	w3ft09 (VLN, GN, PLN, EPS, FL, WORK, TRIGS, RCOS)
	Computes 2.5 x 2.5 n. More...

Detailed Description

Computes 2.5x2.5 n.

hemi. grid-vector

Author

Joe Sela

Date

1980-10-21

Definition in file w3ft09.f.

Function/Subroutine Documentation

w3ft09()

subroutine w3ft09	(	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 n.

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
1980-10-21	JOE SELA	Initial.
1981-06-15	Ralph Jones	Add doc block, clean up source.
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]	VLN	992 complex coeff.
[in]	PLN	992 space for legendre polynomials.
[in]	EPS	992 real space for coeffs. used in computing pln.
[in]	FL	31 complex space for fourier coeff.
[in]	WORK	144 work space for subr. w3ft12
[in]	TRIGS	216 precomputed trig funcs. Used in w3ft12(), computed by w3fa13()
[in]	RCOS	37 reciprocal cosine latitudes of 2.5 x 2.5 grid must be computed before first call to w3ft11() using sr w3fa13.
[out]	GN	(145,37) grid values. 5365 point grid is type 29 or 1d 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

1980-10-21

Definition at line 40 of file w3ft09.f.