function plot2(y)
% plot 2D array (ACF, RDF, etc.) as a waterfall plot

global sr;			% sampling rate

waterfall(y); view(10, 70);  
colormap([0 0 0]); 
set (gca, 'FontSize', 14); set(get(gca, 'XLabel'), 'String', 'lag (ms)');
ticks = [0, 2.5, 5, 7.5];	% ms - tick values
set (gca, 'XTick', ticks * sr / 1000); 
set (gca, 'XTickLabel', ticks);
if (sr == 10000)
	set (gca, 'YTick', linspace(1, size(y, 1), 6));
	set (gca, 'YTickLabel', [0.1, 0.34, 0.77, 1.5, 2.8, 0.5]);
	set(get(gca, 'YLabel'), 'String', 'kHz');
end
set (gca, 'ZTick', []);
%pcolor(zzz);