Without even reading the XTICKLABELS documentation lets first do some basic reasoning:
- is a single character vector. XTICKLABELS has no way to distinguish between what the user incorrectly thinks are different labels. There is no reason to expect this to work.
- is a cell array of string scalars. In other words, you are placing lots of scalar container arrays inside another container array, which as the documentation clearly states has none of the benefits of string arrays and is unlikely to work with most MATLAB functions. There is no reason to expect this to work.
- a string array should work exactly as expected.
Now lets read the XTICKLABELS documentation. It clearly states the the labels input must be a "cell array of character vectors | string array | categorical array". So according to the XTICKLABELS documentation 1. and 2. are not supported, which exactly matches our reasoning above.
So lets try a string array (which the XTICKLABELS documentation states is supported):
xlabel("x")
ylabel("y")
xlim([-2*pi,2*pi])
xticks(-2*pi:pi/2:2*pi)
mylabels= ["$-2\pi$","$-\frac{3\pi}{2}$","$-\pi$","$-\frac{\pi}{2}$","0~~~~","$\frac{\pi}{2}$","$\pi$","$\frac{3\pi}{2}$","$2\pi$"];
xticklabels(mylabels)
ax=gca;
ax.TickLabelInterpreter='Latex';
We can see that it works exactly as expected.
"I would like to understand what's the problem here."
The problems are most likely:
- the user does not read the XTICKLABELS documentation,
- the user does not understand what square brackets do,
- the user made some mistakes in their implementation of a string array,
- the user has unrealisic expectations of container arrays generally.
