C
C MONGO PLOTTING ROUTINE WITH USER DEFINED SPECIFICS
C DEVELOPED BY SAUNDERS B. KRAMER JR., CODE 692
C
C XX1     PLOT LOWER X AXIS LIMIT IN DEVICE COORDINATES - R*4
C XX2     PLOT UPPER X AXIS LIMIT IN DEVICE COORDINATES - R*4
C YY1     PLOT LOWER Y AXIS LIMIT IN DEVICE COORDINATES - R*4
C YY2     PLOT UPPER Y AXIS LIMIT IN DEVICE COORDINATES - R*4
C XT1     Y LABEL LOWER X AXIS LIMIT IN DEVICE COORDINATES - R*4
C XT2     Y LABEL UPPER X AXIS LIMIT IN DEVICE COORDINATES - R*4
C YT1     X LABEL LOWER Y AXIS LIMIT IN DEVICE COORDINATES - R*4
C YT2     X LABEL UPPER Y AXIS LIMIT IN DEVICE COORDINATES - R*4
C TT1     TITLE LOWER Y AXIS LIMIT IN DEVICE COORDINATES - R*4
C TT2     TITLE UPPER Y AXIS LIMIT IN DEVICE COORDINATES - R*4
C XNUMH   SIZE OF X SCALE CHARACTERS - R*4
C YNUMH   SIZE OF Y SCALE CHARACTERS - R*4
C XTXTH   SIZE OF X LABEL CHARACTERS - R*4
C YTXTH   SIZE OF Y LABEL CHARACTERS - R*4
C TITLH   SIZE OF TITLE CHARACTERS - R*4
C XLAB    CONTROLS X AXIS SCALING AND LABELLING - I*4
C   0 PRINT ALL SCALES AND X LABEL
C   1 SKIP FIRST SCALE
C   2 SKIP LAST SCALE
C   3 SKIP FIRST AND LAST SCALE
C   4 NO SCALES 
C YLAB    PARALLELS XLAB ABOVE FOR Y AXIS - I*4
C XTLEN   SIZE OF X AXIS LARGE TICKS - R*4
C YTLEN   SIZE OF Y AXIS LARGE TICKS - R*4
C XSTRING X LABEL STRING - C*50
C YSTRING Y LABEL STRING - C*50
C TITLE TITLE STRING - C*50
C TYPE INDICATES INDEPENDENT AXIS FORMAT - I*4
C  -6 TIME FORMAT (YEAR//DAY) YEAR INTERVALS
C  -5 TIME FORMAT (YEAR)       *
C  -4 TIME FORMAT (HOUR)      DAY INTERVALS
C  -3 TIME FORMAT (DAY)        *  
C  -2 TIME FORMAT (DAY//HOUR)  *
C  -1 TIME FORMAT (YEAR//DAY)  *
C   0 STANDARD
C   1 LOGARITHMIC INDEPENDENT AXIS, STANDARD Y AXIS
C   2 LOGARITHMIC DEPENDENT AXIS, STANDARD X AXIS
C   3 LOGARITHMIC INDEPENDENT AND DEPENDENT AXIS
C XLOW    PLOT LOWER X AXIS LIMIT IN USER COORDINATES - R*4
C XHIGH   PLOT UPPER X AXIS LIMIT IN USER COORDINATES - R*4
C YLOW    PLOT LOWER Y AXIS LIMIT IN USER COORDINATES - R*4
C YHIGH   PLOT LOWER Y AXIS LIMIT IN USER COORDINATES - R*4
C SSPANX  SPACING OF INDEPENDENT AXIS SMALL TICKS - R*4
C BSPANX  SPACING OF INDEPENDENT AXIS LARGE TICKS - R*4
C SSPANY  SPACING OF DEPENDENT AXIS SMALL TICKS - R*4
C BSPANY  SPACING OF DEPENDENT AXIS LARGE TICKS - R*4
C XFORM   FORTRAN FORMAT OF INDEPENDENT AXIS SCALING - C*10
C YFORM   FORTRAN FORMAT OF DEPENDENT AXIS SCALING - C*10
C
      SUBROUTINE GRID(XX1,XX2,YY1,YY2,XT1,XT2,YT1,YT2,TT1,TT2,
     C                XNUMH,YNUMH,XTXTH,YTXTH,TITLH,XLAB,YLAB,
     C                XTLEN,YTLEN,XSTRING,YSTRING,TITLE,TYPE,
     C                XLOW,XHIGH,YLOW,YHIGH,SSPANX,BSPANX,
     C                SSPANY,BSPANY,XFORM,YFORM)
      CHARACTER*1 TCHAR
      CHARACTER*10 VALUE,XFORM,YFORM
      CHARACTER*50 XSTRING,YSTRING,TITLE
      INTEGER*4 XNUM,YNUM,XLAB,YLAB,TYPE
      LOGICAL TIME
      REAL*8 TLOW,THIGH,DEC,CONVERT
C
C DETERMINE IF INDEPENDENT AXIS HAS TIME SCALE
C
      TIME = .FALSE.
      IF (TYPE.LT.0) TIME = .TRUE.
      IF (.NOT.TIME) GOTO 30
C
C CONVERT CALENDAR TIME INTO DECIMAL YEAR
C
       TLOW = CONVERT(XLOW)
       THIGH = CONVERT(XHIGH)
   30 CONTINUE
C
C DRAW BOX
C
      CALL MGOSETLOC(XX1,YY1,XX2,YY2)
      CALL MGOLINE(XX1,YY1,XX1,YY2)
      CALL MGOLINE(XX1,YY2,XX2,YY2)
      CALL MGOLINE(XX2,YY2,XX2,YY1)
      CALL MGOLINE(XX2,YY1,XX1,YY1)
C
C DRAW TIME (INDEPENDENT) AXIS TICK MARKS
C
      IF (.NOT.TIME) GOTO 40
       CALL MGOSETEXPAND(XNUMH)
       CALL BIGTICK(XX1,XX2,YY1,YY2,TLOW,THIGH,BSPANX,
     C              XLAB,XTLEN,TYPE)
       CALL SMALLTICK(XX1,XX2,YY1,YY2,TLOW,THIGH,SSPANX,
     C              XTLEN,TYPE)
      GOTO 45
   40 CONTINUE       
C
C DRAW INDEPENDENT AXIS LARGE TICK MARKS AND LABEL
C
      IF (TYPE.EQ.1.OR.TYPE.EQ.3) THEN
       ISCALE = 1
      ELSE 
       ISCALE = 0
      END IF
      CALL MGOSETEXPAND(XNUMH)
      CALL LRGTICK(YY1,YY2,XX1,XX2,XLOW,XHIGH,BSPANX,
     C             XFORM,XTLEN,XLAB,ISCALE)
C
C DRAW INDEPENDENT AXIS SMALL TICK MARKS
C
      IF (TYPE.EQ.1.OR.TYPE.EQ.3) THEN
       CALL LOGTICK(YY1,YY2,XX1,XX2,XLOW,XHIGH,SSPANX,XTLEN)
      ELSE
       CALL SMLTICK(YY1,YY2,XX1,XX2,XLOW,XHIGH,SSPANX,XTLEN)
      END IF
C
   45 CONTINUE
C 
C DRAW DEPENDENT AXIS LARGE TICK MARKS AND LABEL 
C
      IF (TYPE.EQ.2.OR.TYPE.EQ.3) THEN
       ISCALE = 1
      ELSE
       ISCALE = 0
      END IF
      CALL MGOSETEXPAND(YNUMH)
      XX1 = -XX1
      CALL LRGTICK(XX1,XX2,YY1,YY2,YLOW,YHIGH,
     C             BSPANY,YFORM,YTLEN,YLAB,ISCALE)
C
C DRAW DEPENDENT AXIS SMALL TICK MARKS 
C
      XX1 = -XX1
      IF (TYPE.EQ.2.OR.TYPE.EQ.3) THEN
       CALL LOGTICK(XX1,XX2,YY1,YY2,YLOW,YHIGH,SSPANY,YTLEN)
      ELSE
       CALL SMLTICK(XX1,XX2,YY1,YY2,YLOW,YHIGH,SSPANY,YTLEN)
      END IF
C
C LABEL TITLE
C
      CALL STRINGSET(XX1,TT1,XX2,TT2,TITLE,50,1,TITLH)
C
C LABEL INDEPENDENT AXIS
C
      CALL STRINGSET(XX1,YT1,XX2,YT2,XSTRING,50,1,XTXTH)
C
C LABEL DEPENDENT AXIS
C
      CALL MGOSETANGLE(90.)
      CALL STRINGSET(XT1,YY1,XT2,YY2,YSTRING,50,1,YTXTH)
      CALL MGOSETANGLE(0.)
C
C RESET LOCATION,SIZE AND WEIGHT
C
      CALL MGOSETLOC(XX1,YY1,XX2,YY2)
      CALL MGOSETEXPAND(1.0)
      CALL MGOSETLWEIGHT(1)
C
      RETURN
      END