% 2011-02-01  Michele Tavella <michele.tavella@epfl.ch>

N = 100;
Nc = 4;
Nk = 3;
D = rand(Nc, Nk, N);

bars         = {};
bars.x       = 1:1:Nc;
bars.w       = 0.18;
bars.dx      = [-0.25 0.00 0.25];
bars.colors  = {[1.00 0.00 0.00], ...
				[0.00 1.00 0.00], ...
				[0.00 0.00 1.00]};
bars.classes = {'Class 1', ...
				'Class 2', ...
				'Class 3'};
bars.groups  = {'Group 1', ...
				'Group 2', ...
				'Group 3'};

figure(1);
clf;
for ik = 1:Nk
	Dik = squeeze(D(:, ik, :));
	Mik = mean(Dik, 2);
	Sik = std(Dik, [], 2);

	hold on;
	h = bar(bars.x + bars.dx(ik), Mik, 'FaceColor', bars.colors{ik});
	set(h, 'BarWidth', bars.w);
	errorbar(bars.x + bars.dx(ik), Mik, Sik, ...
		'.k', ...
		'MarkerSize', 1, ...
		'HandleVisibility','off');
	hold off;
end
h = legend(bars.classes, 'Location', 'NorthEast');
set(h, 'EdgeColor', 'white');
set(gca, 'XTick', [1:1:Nc]);
set(gca, 'XTickLabel', bars.groups);
grid on;
box on;
ylim([0, 1]);