CALL SEQUENCE...
       hovplot  Z INPUT OUTPUT [ -a VAL1 -b VAL2  -c VAL3 -d VAL4   \ 
                                 -i VAL5    VAL6  -j VAL7    VAL8   \ 
                                 -k VAL9    VAL10    VAL11          \ 
                                 -m VAL12   VAL13 -n VAL14   VAL15  \ 
                                 -label    "VAL16"  "VAL17" "VAL18" \ 
                                 -kind      VAL19    VAL20 ] 
 
 
      DESCRIPTION...
       hovplot - PRODUCES HOVMUELLER DIAGRAMS OF A TIME SERIES 
                 OF SINGLE VERTICAL LEVEL ZONAL FILES
 
 
      AUTHOR  - F. Zwiers, APR 07/86.
      LAST REVISION: $Header: First-release @ 2015-01-07 16:36:15 -0500 (Bernard Dugas) $
 
 
      INPUT FILE...
       Z = FILE OF TIME SERIES OF SLICES ON A SINGLE LEVEL
 
 
      INPUT PARAMETERS...
 
      ... FIRST LINE ...
 
       SCAL   (a) = SCALING FACTOR. IF SCAL = 0. THEN SCAL,FLO,HI AND
                    FINC ARE CHOSEN BY THE PROGRAM.
       FLO    (b) = LOWEST VALUE TO BE CONTOURED
       HI     (c) = HIGEST VALUE TO BE CONTOURED
       FINC   (d) = CONTOUR INTERVAL (A MAX. OF 40 CONTOURS IS PERMITTED)
       AR (kind1) = ASPECT RATIO = LENGTH OF Y-AXIS / LENGTH OF XAXIS
                    IF AR<=0 THE DEFAULT PLOT IS DRAWN WITH ASPECT RATIO
                    DETERMINED FROM THE LENGTH OF RECORD AND NUMBER OF
                    RECORDS
          (kind2) = IGNORED VALUE FOR CONTOURING ROUTINES (DEF = 10.E37).
       NXLAB (i1) = NUMBER OF POINTS ON THE X-AXIS WHICH ARE LABELED
                    (DEFAULT IS 0)
       NYLAB (j1) = NUMBER OF POINTS ON THE Y-AXIS WHICH ARE LABELED
                    (DEFAULT IS 0)
       FLIP  (k1) = SWITCH TO FLIP THE Y-AXIS DATA BEFORE DRAWING.
                    (0 MEANS DO NOT DO IT, .NOT.0 DO IT)
       NXTIC (i2) = NUMBER OF TICKS BETWEEN LABELS ON THE X-AXIS
                    (DEFAULT IS 0)
       NYTIC (j2) = NUMBER OF TICKS BETWEEN LABELS ON THE Y-AXIS
                    (DEFAULT IS 0)
       MS    (k2) = LINE PRINTER MAP SCALE FACTOR (OMITTED IF MS=0).
                    IF MS < 0 THEN MS=ABS(MS+1) AND THE PUBLICATION
                    QUALITY OPTION IS SET.
       LHI   (k3) = 0, HIGHS AND LOWS LABELLED,
                  =-1, .. NOT LABELLED.
 
  110  READ(5,5010) SCAL,FLO,HI,FINC,AR,NXLAB,NYLAB,
     +              FLIP,NXTIC,NYTIC,MS,LHI
 5010 FORMAT(10X,5E10.0,1X,2I2,1X,2I2,3X,I2,1X,2I2)
 
 
      ... SECOND LINE ...
 
       XLAB (label1) = 16 CHARACTER LABEL FOR X-AXIS.
       XMIN (m1)  = VALUE OF LABEL AT LEFT  HAND END OF X-AXIS
       XMAX (m2)  = VALUE OF LABEL AT RIGHT HAND END OF X-AXIS
                    (XMIN=XMAX TURNS OFF LABELING OF TICKS ON X-AXIS)
       YLAB (label2) = 16 CHARACTER LABEL FOR Y-AXIS.
       YMIN (n1)  = VALUE OF LABEL AT LEFT  HAND END OF Y-AXIS
       YMAX (n2)  = VALUE OF LABEL AT RIGHT HAND END OF Y-AXIS
                    (YMIN=YMAX TURNS OFF LABELING OF TICKS ON Y-AXIS)
 
       READ(5,5020) XLAB,XMIN,XMAX,YLAB,YMIN,YMAX
 5020 FORMAT(A16,4X,2E10.0,A16,4X,2E10.0)
 
 
      ... THIRD LINE ...
 
       LABEL (label3) = 80 CHARACTER LABEL FOR CONTOUR MAP.
 
       READ(5,5030) LABEL
 5030 FORMAT(A80)
 
 
      EXAMPLE OF INPUT CARDS...
 
   HOVPLOT        1.      -40.       40.        2.       0.9  2 5   39    0  0 0
     SEASON                1.0      40.0    LATITUDE             -90.0      90.0
   SEASONAL MEAN ZONAL SURFACE PRESSURE VS TIME FOR RUN FJ (FIRST 40 SEASONS)
 
         01234567890123456789012345678901234567890123456789012345678901234567890
         1         2         3         4         5         6         7         8
 
 
      EXIT CONDITIONS...
        0 NO PROBLEMS
 
      FATAL CONDITIONS...
        1 UNABLE TO READ FIRST DIRECTIVE LINE
        2 INCOMPLETE DIRECTIVE SET (NO FIRST LABEL LINE)
        3 INCOMPLETE DIRECTIVE SET (NO SECOND LABEL LINE)
        4 UNABLE TO READ SECOND DIRECTIVE LINE
 
      NON-FATAL CONDITIONS...
      101 FINISHED READING Z
      102 THE SECOND RECORD DIMENSION MUST BE 1
      103 RECORDS LARGER THAN 200000 WORDS
      104 MORE THAN ONE SIZE OF RECORDS