CALL SEQUENCE...
       plagalc   GALCFLD PLFLD PHI PHIS INPUT OUTPUT \
                 [ -n VAL1 -t1 VA2 -kind VAL3 -a VAL4 -b VAL5 -c VAL6 -def ]
 
 
      DESCRIPTION...
       plagalc - INTERPOLATES GAL-CHEN LEVEL GRIDS FROM PRESS. LEVELS FOR RCM
 
 
      AUTHOR  - M.GIGUERE
      LAST REVISION: $Header: /home/cvs/RMNLIB/utils/rdiag/lspgm/plagalc.ptn,v 4.12 2014/09/25 20:20:52 dugas Exp $
 
 
      PURPOSE - CONVERTS A PRESSURE LEVEL GAUSSIAN GRID DATASET OF INITIAL
                MODEL VARIABLES (TEMP,U,V OR ES) TO A GAL-CHEN LEVEL
 
 
      INPUT FILES...
       PLFLD  = INPUT FIELD ON PRESSURE LEVELS. (T,U,V OR ES)
       PHI    = GEOPOTENTIAL HEIGHT (VARIABLE NAME: 'PHI'  OU 'GZ')
       PHIS   = OROGRAPHY (FOR RCM) (VARIABLE NAME: 'PHIS' OU 'MT')
 
      OUTPUT FILE...
       GALCFLD= INTERPOLATED DATASET ON GALC-CHEN LEVELS.
 
 
      INPUT PARAMETERS...
 
       NPSL   (n)    = NUMBER OF REQUESTED PSEUDO-SIGMA LEVELS, (DEF=5, MAX 999).
                       IF NTHL IS NEGATIVE, EACH -NTHL LEVTH VALUES ARE READ WITH
                       A I10 FORMAT OR AN E10.0 IF ITS VALUE CONTAINS A DECIMAL
                       POINT.
       TMOYEN (t1)   = MEAN TEMPERATURE (USED FOR TRANSFORM PRESS. TO P-SIGMA LEVELS)
       HTOIT  (a)    = HEIGHT(M) AT THE LID OF MODEL.
       RLUP   (b)    = LAPSE RATE USED TO EXTRAPOLATE UPWARDS.
       RLDN   (c)    = LAPSE RATE USED TO EXTRAPOLATE DOWNWARDS.
       COORD  (kind) = 'GALC' OR BLANK, FOR GALC-CHEN VERTICAL COORDINATES.
 
       PSIG          = PSEUDO-SIGMA  LEVELS (MB). THE DEFAULTS ARE
                       AS SPECIFIED IN THE EXAMPLE BELOW.
 
       Notes: 1) The first input line is NOT read if any command-line
                 parameters are passed.
              2) Furthermore, the second line will not be read either
                 if the "-def" defaults processing mode is requested.
 
       READ( 5,5010) NPSL,TMOYEN,RLUP,RLDN,COORD,HTOIT
       IF (NPSL.GT.0)
       READ( 5,5020 ) (PSIG(I),I=1,NPSL)
       IF (NPSL.LT.0)
       READ( 5,5030 ) (PSIG(I),I=1,-NPSL)
 5010  FORMAT(10X,I5,3E10.0,1X,A4,E10.0)
 5020  FORMAT(16E5.0)
 5030  FORMAT(8E10.0)
 
 
      EXAMPLE OF INPUT CARDS...
 
  PLAGALC.    5      220.        0.        0. GALC    40000.
 .100 .300 .500 .850 1.00
 
         0123456789012345678901234567890123456789012345678901234567890
         1         2         3         4         5         6         7
 
 
      EXIT CONDITIONS...
        0 NO PROBLEMS
        1 ILLEGAL COORD VALUE
        2 NPSL LARGER THAN ALLOWED
        3 LSIG IS NOT MONOTONICALLY INCREASING
        4 NOT ENOUGH *OR* TOO MANY LEVEL *OR* NOT THE
          SAME NUMBER OF VERTICAL LEVELS IN PLFLD AND PHI
        5 PLFLD,PHI AND PHIS NOT THE SAME HORIZONTAL SIZE
        6 UNABLE TO READ PHIS
        7 FOUND HEIGHT OF LSIG LEVELS TO BE HIGHER THAN HTOIT
        8 UNABLE TO READ FIRST SET OF PLFLD
        9 MORE THAN ONE SIZE IN PLFLD
       10 UNABLE TO READ A SET OF PHI
       11 MORE THAN ONE SIZE IN PHI
       12 PROBLEMS READING FIRST DIRECTIVE CARD
       13 PROBLEMS READING SECOND DIRECTIVE CARD
       14 PSIG DOES NOT CONTAIN GAL-CHEN DATA
       15 UNABLE TO ALLOCATE WORKING MEMORY