Plot step function with y-axis in log-scale

Hi,

How can I plot something like this?

I can only either use semilogy to plot the graph in log scale (without step function), or plot the step function (using "stairs" function) but with the y-axis in terms of the exponential (by taking the log of the y-values first).

How do I do both?

Thank you.

[Azzi Abdelmalek]

The question is not clear

[Rayne]

Basically, I'm trying to create the type of plot in the given picture, i.e. step function on a log-scale y-axis. I could only get either a smooth curve on a log scale, or a step function on a non-log-scale. How do I do both?

Answer 1

[Walter Roberson]

If you are trying to get one line to be in log y scale and another to be in linear y scale, then you should plotyy() and set one of the axes to 'yscale' 'log'

If you are having problems that somehow stairs() does not look right with semilogy, then I do not seem to reproduce that in R2014a.

But if you happen to need some code to reproduce stairs() in terms of plot(), then:

plot( [x(1),kron(x(2:end),[1 1])], [kron(y(1:end-1),[1 1]),y(end)] )

[Rayne]

Thanks, I managed to plot it using something like

stairs(1:10, 2*(1:10));
set(gca, 'YScale', 'log')