problems with my contour plot

my second contour plot with time, is not starting to plot at (0,0), which it's supposed to. Not sure why

 m = 8;
ft = 40;
b = linspace(20,200,10);
k = linspace(20,200,10);
for j = 1:length(b)
    for i = 1:length(b)
    b1 = b(j);
    k1 = k(i); 
    G = tf([1],[m b1 k1]);
    sys = ft*G;
    [y,t] = impulse(sys);
   disp(j,i) = max(y);
   time(j,i) = max(t);

    end
end
figure(1)
contourf(k,b,disp)
figure(2)
contourf(k,b,time)

Answer 1

[Walter Roberson]

Your k and b start at 20, so you do not have data for 0, 0. You could force the plot to start at 0, 0:

xlim([0 200]);ylim([0 200])