function diehist(x)
% plots a normalized histogram of integer random numbers x 
% drawn from rolling a die.
maxx = max(x);
[h,b] = hist(x, 1:maxx);
h = h/sum(h);   % normalization
plot([0 maxx+1], [1/maxx 1/maxx], 'r', 'linewidth', 3)
hold on
bar(b, h);
hold off
set(gca, 'XTick', 1:maxx);
xlim([ 0, maxx+1]);
xlabel('Eyes');
ylabel('Probability');
end