%Neat animatied graph example
for F = 1:5000
clf
for FF = 1:5
phase = (F+FF)/30*2*pi;
x = [0:0.01:4*pi];
y = sin(x+phase)./(1+x)*3;
plot(x, y)
deriv = diff(y)./diff(x);
hold on 
plot(x, [deriv 0], 'color', 'r')
axis([0 12 -4 4])
end
pause(1/30);
end