Change colors of lines from an iterated plot function.

I'm plotting different values of beta using a for loop. But the color is the same for each line plotted. How can I also iterate a color change? This is the code in the file that will call the function.

%%Lab 2_1
b = [6,30,60,400];
type susp
for n = 1:4;
susp(1,900,b(n))
hold on
end
hold off

This is the function that I am calling.

function susp(M, k, beta)
% SUSP Simulate suspension
% susp(M, k, beta)
%
% Produces a plot of the displacement of the suspension, x,
% as a function of time, given parameters
% M (mass), k (spring constant) and beta (damping)

t = -1:0.001:2;
f =  u(t);
F=k;
sys = tf(F/M, [1 beta/M k/M]);
y = lsim(sys, f, t);
plot (t, f, 'b', t, y,'r', 'lineWidth',2);
ylim([-0.5 1.5]);
grid on;
return

Answer 1

[Chad Greene]

The problem is the 'b' and the 'r' in the plot function. They're setting all lines to blue or red. Try this:

plot(t,f,t,y,'lineWidth',2);