Functions/Subroutines
subroutine	w3ft38 (FLN, GN, PLN, FL, WORK, TRIGS)
	SUBPROGRAM: W3FT38 COMPUTES 2.5 X 2.5 N. More...

Function/Subroutine Documentation

◆ w3ft38()

subroutine w3ft38	(	complex, dimension( 31 , 31 )	FLN,
		real, dimension(145,37)	GN,
		real, dimension( 32, 31, 37 )	PLN,
		complex, dimension( 31 )	FL,
		real, dimension(144)	WORK,
		real, dimension(216)	TRIGS
	)

SUBPROGRAM: W3FT38 COMPUTES 2.5 X 2.5 N.

HEMI. GRID-SCALER AUTHOR: R.E.JONES ORG: W323 DATE: 93-07-23

ABSTRACT: COMPUTES 2.5 X 2.5 N. HEMI. GRID OF 145 X 37 POINTS FROM SPECTRAL COEFFICIENTS IN A RHOMBOIDAL 30 RESOLUTION REPRESENTING A SCALER FIELD.

PROGRAM HISTORY LOG: 93-07-23 R.E.JONES NEW VERSION OF W3FT08, TAKES OUT W3FA12 MAKES PLN 3 DIMENSIONS, PLN IS COMPUTED ONE TIME IN MAIN PROGRAM, TRADES MEMORY FOR MORE SPEED. W3FA12 USED 70% OF CPU TIME.

USAGE: CALL W3FT38(FLN,GN,PLN,FL,WORK,TRIGS)

INPUT VARIABLES: NAMES INTERFACE DESCRIPTION OF VARIABLES AND TYPES

FLN ARG LIST 961 COMPLEX COEFF. PLN ARG LIST (32,31,37) REAL SPACE WITH LEGENDRE POLYNOMIALS COMPUTED BY W3FA12. FL ARG LIST 31 COMPLEX SPACE FOR FOURIER COEFF. WORK ARG LIST 144 REAL WORK SPACE FOR SUBR. W3FT12 TRIGS ARG LIST 216 PRECOMPUTED TRIG FUNCS. USED IN W3FT12, COMPUTED BY W3FA13

OUTPUT VARIABLES: NAMES INTERFACE DESCRIPTION OF VARIABLES AND TYPES

GN ARG LIST (145,37) GRID VALUES. 5365 POINT GRID IS TYPE 29 OR 1D HEX O.N. 84

SUBPROGRAMS CALLED: NAMES LIBRARY

AIMAG CMPLX REAL SYSTEM
W3FT12 W3LIB

WARNING: W3FT08 WAS OPTIMIZED TO RUN IN A SMALL AMOUNT OF MEMORY, IT WAS NOT OPTIMIZED FOR SPEED, 70 PERCENT OF THE TIME WAS 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 THE RUNNING TIME WAS CUT 70 PERCENT. ADD FOLLOWING CODE TO MAIN PROGRAM TO COMPUTE EPS, PLN, TRIGS, AND RCOS ONE TIME IN PROGRAM.

DOUBLE PRECISION EPS(992)         (REAL ON CRAY)
DOUBLE PRECISION COLRA            (REAL ON CRAY)

REAL             PLN( 32, 31, 37 )
REAL             RCOS(37)
REAL             TRIGS(216)

DATA  PI /3.14159265/

DRAD = 2.5 * PI / 180.0
CALL W3FA11(EPS,30)
CALL W3FA13(TRIGS,RCOS)
DO LAT = 1,37
  COLRA = (LAT - 1) * DRAD
  CALL W3FA12 (PLN(1,1,LAT), COLRA, 30, EPS)
END DO

ATTRIBUTES: LANGUAGE: CRAY CFT77 FORTRAN MACHINE: CRAY Y-MP8/864, CRAY Y-MP EL2/128

Definition at line 73 of file w3ft38.f.

Functions/Subroutines

Function/Subroutine Documentation

◆ w3ft38()