Set equal limits for y-axis for two figures

Question

How can I make the vertical axes of two plots equal?

For example:

a = [1 2 3; 21 1 3; 4 2 3; 4 5 6]

After plotting plot(a(1, :)) I get the following figure:

I have done some simple operations:

[U E V] = svd(a);
figure(2);
plot(U(1,:))

And get another figure:

How do I make the y-axis limits of both plots equal? Is it with the axes equal command?

UPDATE:
I've used the following commands:

figure (1)
ylim([0 3])
plot(a(1,:))
figure (2);
ylim([0 3])
plot(U(1,:))

But get the same result...

Answer 1

You can use ylim to force limits on the y-axis. For example:

figure(1)
%// Some plotting...
ylim([0 3])

figure(2)
%// Some more plotting
ylim([0 3])

This ensures that the y-axis is limited to the range [0, 3] in both plots. You can do the same for the limits of the x-axis with the command xlim.

Also note that if you want to set the limits for both axes at once, instead of using xlim and ylim (two commands), you can use axis (one command).