SUBROUTINE SCATPL

   SCATPL plots data point pairs (x,y) in a scatter plot format using  log and/or  linear scaling including appropriate axes and plot title. Several different sets of data may be plotted on the same plot by specifying different plotting symbols for each set of data points. Various options select the format of plotting. If nl=1 then the x and y arrays may be 1d arrays.

CALL SCATPL(x,y,nl,np,iflag,nsym,s,xl,yl,xt,nxt,yt,nyt,
                t,nt,<xm,xx,ym,yx<,ic>>)

x     (R): array of x values dimensioned x(np,nl)
y     (R): array of y values dimensioned y(np,nl)
nl    (I): number of symbol types (if nl=1, x,y may be 1d arrays)
np    (I): number of data point pairs (x,y) of same symbol type
iflag (I): option flag
           < 0 : do not close LONGLIB after plotting
           = 0 : close LONGLIB--no plot produced
           > 0 : close LONGLIB after plotting
 (magnitude) > 10000 : do not initialize LONGLIB before plotting
   (1's digit)  = 1 : plot x linear, y logarithmic (base 10)
                = 2 : plot x logarithmic, y linear
                = 3 : plot x logarithmic, y logarithmic
                = 4 : plot x linear, y linear
   (10's digit) = 0 : no axes or title plotted
                = 1 : axes with axis line/ticks on top and sides
                = 2 : plot solid cartesian grid
                = 3 : plot ticked cartesian grid without box
                = 4 : plot ticked cartesian grid with box
                = 5 : plot ticked cartesian grid, box w/axis ticks
                = 6 : plot without box or cartesian grid
                = 7 : plot solid logarithmic grid
                = 8 : plot dotted logarithmic grid
                = 9 : plot ticked logarithmic grid
   (100's)      = 0 : Ask which screen device to use
               <> 0 : Screen Device Number (see FRAME)
nsym  (I): array of symbols numbers dimensioned nsym(nl)
           nsym(n) <  0 : dots only plotted, no symbols line n
           nsym(n) >= 0 : plot symbol number for line n
s     (R): size of symbols (if s <= 0, 0.1 is used)
xl    (R): x axis length in inches (integer-valued)
           < 0 : use input scaling in xm,xx
           > 0 : use auto scaling computed from input array
yl    (R): y axis length in inches (integer-valued)
           < 0 : use input scaling in ym,yx
           > 0 : use auto scaling computed from input array
xt    (C): x axis title string
nxt   (I): number of characters in xt
           < 0 : axis ticks on top of x axis
           = 0 : no axis
           > 0 : axis ticks on bottom of x axis (normal)
yt    (C): y axis title string
nyt   (I): number of characters in yt
           < 0 : axis ticks on right of y axis
           = 0 : no axis
           > 0 : axis ticks on left of y axis (normal)
t     (C): plot title string
nt    (I): number of characters in t
           < 0 : use color array
           = 0 : no title
           > 0 : do not use color array
xm    (R): minimum value of x array (accessed if xl or nt < 0)
xx    (R): maximum value of x array (accessed if xl or nt < 0)
ym    (R): minimum value of y array (accessed if xl,yl or nt<0)
yx    (R): maximum value of y array (accessed if xl,yl or nt<0)
(NOTE: color array accessed if nt < 0 or |nt|/100 >0)
ic    (I): color list
           ic(1) : color for grid
           ic(2) : color for axis lines
           ic(3) : color for axis numbers
           ic(4) : color for axis titles
           ic(5) : color for axis exponents
           ic(6) : color for title (return)
           ic(7) : color for plotted line 1
           ic(8) : color for plotted line 2
           ic(9) :    etc.

common /cscatpl/xmr,dxr,ymr,dyr

xmr   (R): returned value of xmin
dxr   (R): returned value of scale factor (xmax-xmin)/xlen
ymr   (R): returned value of ymin
dyr   (R): returned value of scale factor (ymax-ymin)/ylen