W3FT40

The W3FT40 routine computes 2.5 x 2.5 S. HEMI. grid 
           of 145 x 37 points from spectral coefficients in
           a Rhomboidal 30 resolution representing a scaler field.

USAGE:  CALL W3FT40(FLN,GN,PLN,FL,WORK,TRIGS)

   Input variables:
      FLN        961 COMPLEX COEFF.
      PLN        (32,31,37) REAL SPACE WITH LEGENDRE POLYNOMIALS
                 COMPUTED BY W3FA12.
      FL         31 COMPLEX SPACE FOR FOURIER COEFF.
      WORK       144 REAL WORK SPACE FOR SUBR. W3FT12
      TRIGS      216 PRECOMPUTED TRIG FUNCS. USED
                 IN W3FT12, COMPUTED BY W3FA13
 
    Output variables:
      GN         (145,37) GRID VALUES.
                 5365 POINT GRID IS TYPE 30 OR 1E O.N. 84
 
REMARKS:
    W3FT10 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.
 
 


  
W3lib.tar
  
Library contains Fortran 90 decoder/encoder
   routines for GRIB edition 1. (Fortran90) 

   Date posted: 2/22/2007