% operand stack configuration in order to use psDrawFilled:
%		psDrawFilled
%		vlist[0].y
%		vlist[0].x
%		n
%		...
%		vlist[n].y
%		vlist[n].x
%		graphics-context dictionary
% this draws lines connecting all the points and fills the
% region with background color (default: 1, or white).

/psDrawFilled
        {	gsave
                newpath
                yVal moveto
                1 sub {
                        yVal lineto
                } repeat
		begin installGC fill end	%% fills with foreground color
                grestore }
        def