SUBROUTINE DONNA( XC, YC, NC, IC, ILINE, XS, YS, NS, IS, DIA, ISYMB )
 This routine is capable of producing a curve that will not pass
 through any of the specified symbols.  The symbols need not be
 located on the curve.  FCTR: DO
 
 XC, YC 	Arrays which contain the coordinates for the
 		curve in units of the axes.
 NC 		Number of points in the above arrays.
 IC	 	Interleave factor.
 ILINE		Type of line, if 0 then only symbols will be
 		generated, see DSHPLT for line types.
 XS, YS		Arrays which contain the coordinates for the
 		symbols in units of the axes.
 NS		Number of points in the above arrays.
 IS		Interleave factor.
 DIA		Diameter of the symbols in inches, if 0. then
 		only the curve will be generated.
 ISYMB		Type of symbol, See SYMBOL.
 
 Note: The coordinates for both the curve and the symbols must such
 that both are plotted from left to right.