##**********************************************************************
## plotstack - Copyright (C) 2005 - Cameron Morland
##   This program is free software; you can redistribute it and/or modify
##   it under the terms of the GNU General Public License as published by
##   the Free Software Foundation; either version 2, or (at your option)
##   any later version.
##
##   This program is distributed in the hope that it will be useful,
##   but WITHOUT ANY WARRANTY; without even the implied warranty of
##   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
##   GNU General Public License for more details.
##**********************************************************************

function x = plotstack(y)

	## we're going to generate the gnuplot script 
	tmp = tempname;
	filename = sprintf("%s.gnuplot", tmp);
	datafile = sprintf("%s.data", tmp);
	psfile = sprintf("%s.eps", tmp);

	out = fopen(filename, "w");

	fprintf(out, "set xtics 1\n");
	fprintf(out, "set output '/dev/null'\nset term x11\n");
	fprintf(out, "set yrange [0:*]\n");

	x = [[1:size(y,1)]', zeros(size(y))];
	fprintf(out, "plot");
	for i = 1:size(y,2)
		x(:,i+1) = sum(y(:,1:size(y,2)+1-i), 2);
		fprintf(out, " '%s' usi 1:%d:(0.8) ", datafile, i + 1);
		fprintf(out, " w boxes fs pattern %d notitle", i);
		if i < size(y,2)
			fprintf(out, ",\\");
		endif
		fprintf(out, "\n");
	endfor

	fprintf(out, "set term postscript eps\n");
	fprintf(out, "set output '%s'\n", psfile);
	fprintf(out, "replot\n");
	eval(sprintf("save -text '%s' x;", datafile));	
	fprintf("Now run \n  load '%s'\nin gnuplot.\n", filename);
	fclose(out);

endfunction