Custom x-axis values in a matlab plot

Question

Currently when I plot a 9 by 6 array, the x-axis of the figure is just 1, 2, 3 up to 9. The Y-axis shows the correct values.

Instead of 1 to 9 I would like the x-axis values to be custom. They should be

100 200 400 1000 2000 5000 10000 20000 50000

instead. I tried

set(gca,'XTick', [100 200 400 1000 2000 5000 10000 20000 50000])

But that's not the correct way to do it. Is there a Matlab option to have these custom values for the x-axis? Why is Matlab just using 1 to 9 anyway?

Solution 1

You should be using xTickLabel instead of XTick.

MATLAB plots every column as a seperate curve. So, that means you have 6 curves and 9 data points for each curve. x-axis data is 1-9 because you did not provide any data for MATLAB to plot with.

Furthermore, you probably want the wrong thing. Doing this will give you equal spacing. It will just replace 1-9 with your array. Since your x-axis data is not equally spaced, it will be weird.

You may want to do it like this:

xdat = [100 200 400 1000 2000 5000 10000 20000 50000];
ydat = rand(9,6); % Your y-axis data
plot(xdat, ydat)

Solution 2

If you want to keep distances between x-values (e.g. 1:9) and only change the labels (not the distances between x-values), try this:

y = rand(9,6);
labels = [100 200 400 1000 2000 5000 10000 20000 50000];
plot(y);
set(gca, 'XTick', 1:length(labels)); % Change x-axis ticks
set(gca, 'XTickLabel', labels); % Change x-axis ticks labels.

Solution 3

Try using

x = [100 200 400 1000 2000 5000 10000 20000 50000];
y = rand(9,6); % Your y-axis data
plot(x, y);
set(gca,'XTick',x); % Change x-axis ticks
set(gca,'XTickLabel',x); % Change x-axis ticks labels to desired values.

Please note that due to the very different values/magnitudes to use un x-axis you can get some x-labels very close (and unreadable)

Comments

[Nicolás Arias]

Is there any way to set set string tick labels? For example, greek letters?