Can't plot reference line in pcolor-plot with logarithmic y-axis

I have code similar to:

h = pcolor(rand(100, 100));
h.EdgeColor = 'none';
line([30 30], [0 100], 'Color', 'red');
set(gca, 'YScale', 'log');

This should plot some random values and draw a vertical line at x = 30. When i debug the code it works until i scale the y-axis, then the line disappears.

Can anyone help me out?

Answer 1

[Robert U]

Hi TIm Hilt,

the problem is that on logarithmic scale zero is not defined thus your line does not have a valid starting point (30,0). Change the y-component to a small but non-zero value and the line reappears.

h = pcolor(rand(100, 100));
h.EdgeColor = 'none';
line([30 30], [1 100], 'Color', 'red');
set(gca, 'YScale', 'log');

Kind regards,

Robert

[Tim Hilt]

Ah ok, i got it. Thank you very much!