How to make a log plot in matlab

Question

Is it possible to make a plot in matlab that does not actually take the logs of the values? I'm plotting wide ranges of values and when I try to make a log plot of them, those below 1 become negative. I would just like it to plot the values on a log scale without taking their logs.

Answer 1

Alternatively, set(gca,'XScale','log') if you have your plot already.

Answer 2

Yes, it is possible. Use the loglog command.

The example from the Mathworks website:

x = logspace(-1,2);   % generate a sequence of points equally spaced logarithmically
loglog(x,exp(x),'-s')
grid on

If you do not want both axes to be log scale, use semilogx or semilogy.