fixed a bug where fragmented categorical data crashed the plot function

[sg-s]

This patch fixes a bug where a categorical array with some categories not being represented crashed the plot function. This was because the plot function looped over the categories, instead of the unique values in the categorical array.

[bastibe]

Cool, thank you!

I see you also changed the X-Tick-Rotation. I'd prefer that not to change, as current users might rely on existing functionality not to change.

You also changed the spelling of a number of set() function calls. Is there a specific reason for that?

[sg-s]

Hi @bastibe I understand about the XTickRotation, I modified the PR to leave it unchanged

As far as I know, the spellings for axis properties use capitalization for every word, as defined in this page:

https://www.mathworks.com/help/matlab/ref/matlab.graphics.axis.axes-properties.html

I believe the format you used may break in the future.

[sg-s]

After some investigation, I learnt this:

the reason your syntax works (with all lower case xtick) is because you're using the old way of modifying axis properties (using set...)

The "new" way does not support all lower-case syntax, e.g.:

ax = gca;
ax.xtick = ... will error
ax.XTick = ...  will work

[bastibe]

Thank you for your investigation.

I fear that the transition from get/set to object properties will be a painful one; Although Mathworks being Mathworks I expect them to keep the old spellings around for a long time.

Regardless, I'm fine with either spelling, so we might as well use the capitalized ones. In truth, I would actually prefer the property syntax, but that only works as of 2017 or so, and too many people are still on older versions, so we can't do that (yet).

Anyway. This looks good to me. Is it ready to merge, do you think?

[sg-s]

should be good!

[bastibe]

Thank you very much for your contribution, then!