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How to change XTick Labels in a heatmap

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Hello I am trying to Change the X ticklabels of a heatmap plot. Apparently, the normal procedure over "xticklabels" is not supported for heatmaps. So I tried out a Workaround, which still has a bug. This is the example:
heatmap(my_matrix, 'Colormap', colorMap, 'ColorbarVisible', 'on', 'XLabel', 'Time', 'YLabel', 'September')
ax = gca;
axp = struct(ax);
axp.Axes.XTickLabel = num2cell(0:23)
This works in the first go, however if I then change the size of my figure (i.e. I expand to full screen), the X ticklabels return back to their original values (which is 1:24). I have also tried to adapt axp.XAxis.TickLabels, which has the same result. Could you give me a hint on what to do?

Accepted Answer

Sean de Wolski
Sean de Wolski on 25 Jan 2018
Edited: Sean de Wolski on 25 Jan 2018
The tick labels are deceptively called *data.
my_matrix = rand(3);
heatmap(my_matrix, 'Colormap', parula(3), 'ColorbarVisible', 'on', 'XLabel', 'Time', 'YLabel', 'September')
ax = gca;
ax.XData = ["Hello" "World" "Thursday"]
Or simply
heatmap(etc..., 'XData', ["Hello" "World" "Thursday"])
Stefanie Aebi
Stefanie Aebi on 25 Jan 2018
Thanks a lot, that perfectly solves the problem.

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More Answers (1)

Brendan Hamm
Brendan Hamm on 25 Jan 2018
A heatmap stores the labels in the XDisplayLabels property. It is not a, but rather a which contains a hidden Axes. There is a reason you get the warning when you pass ax to struct and this is because you are seeing undocumented properties which you are not really meant to interact with. If you see this, you should probably be looking for a documented way of doing this, such as looking at the properties using:
Here we see the documented property XDisplayLabels, and changing this gives the desires result.
ax.XDisplayLabels = num2cell(0:23);
So the moral of the story is that undocumented stuff is nice when you have no other options ... but this should be the last resort!


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