semilogy plot does not have a continuous line going through zero values

Hi I have the following data

x = 1:24 y = [0 0 0 0 2 6 11 15 22 25 27 27 25 20 14 9 4 1 0 0 0 0 0 0]'

I want to use the semilogy plot to only have a log plot on the y axis. However, the line going through the data disappears when y=0. Is there a way to avoid this and show the line going through zero.

thank you

Answer 1

[Jan]

What should appear for the zero? A logarithmic scale has no suitable value for a zero. Try this:

x = 1:24;
y = [0 0 0 0 2 6 11 15 22 25 27 27 25 20 14 9 4 1 0 0 0 0 0 0];
figure;
semilogy(x, y);
figure;
semilogy(x, max(eps, y));

In the second figure, the EPS values appear as 2e-16 (of course). To get a real zero, the scale must be infinitely large.

[Andrew Alkiviades]

thanks it works!