MATLAB: How to get a Negative Positive Negative Y axis labels

Question

Hey Guys,

I have 3 column matrix which I would like to plot as a 3d surf plot with each column representing each axis. The values in Y axis increases from -0.4 to 1.4 and the decreases to -0.4 again. Something like

Y= [-0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.2 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4];

The problem is when I plot it using surf function, the y axis looks like -0.4 to 1.4. and the data is plotted as such, but I would like to plot the values in y axis to first increase and decrease, similar to the data (so the Y axis must have labels same as the data – Negative Positive Negative). But I am always getting the y axis with just increasing values and the x and z values corresponding to the downward slope (1.4 to -0.4) is just plotted as an inverted surface. Is there a solution for this?

Thanks

Answer 1

The y-tick values must be increasing. However you can choose the y-tick labels to be (almost) whatever you want.

Try this:

Y= [-0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.2 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4];
yt = get(gca, 'YTick');                                                         % Get Y-Tick Values
ytx = linspace(min(yt), max(yt), numel(Y));                                     % New Y-Tick Values
ytl = sprintfc('%.1f',Y);                                                       % New Y-Tick Labels
set(gca, 'YTick',ytx, 'YTickLabel',ytl)                                         % Set New Y-Tick Labels

I cannot test this because I do not have your data. It should work.