Matplotlib cannot parse TeX with \text command

[sindzicat]

Hello!

Minimal example:

import matplotlib as plt
fig, ax = plt.subplots()
ax.text(0, 0, r'$s_\text{ind}$')

Result:

ValueError: 
s_\text{ind}
    ^
Expected {accentprefixed | accent | symbol | c_over_c | function | group | frac | dfrac | stackrel | binom | genfrac | sqrt | overline | operatorname}, found 'e'  (at char 4), (line:1, col:5)

As far as I remember, r means raw string, so \t mustn't interpreter as tab. I tried \\t and other ways to avoid this problem but I didn't find any workaround for this case yet... So it seems to me I found a bug.

I use Python 3.8.5 (default, Sep 3 2020, 21:29:08) [MSC v.1916 64 bit (AMD64)],
Matplotlib version is 3.3.1. I tried my code in JupyterLab ver. 2.2.7 on Windows 10.
Matplotlib backend is module://ipykernel.pylab.backend_inline.

Best regards,
Sindzicat.

[anntzer]

\text is not supported, but I agree that it should be, especially because I think it can just be mapped to \mathdefault; in fact \mathdefault/\mathregular (which are synonyms, and which both only exist in Matplotlib and not in TeX or any(?) package that I know of) could be (soft-)deprecated in favor of \text (which is from the pretty standard amsmath).

[sindzicat]

Sorry, I didn't expect, that there are some TeX commands, that aren't supported in Matplotlib yet. Is there any list of (un)suppoted TeX commands in Matplotlib?

[anntzer]

See #14766.

[sindzicat]

@anntzer, many thanks!

[tueda]

It will be nice if the \text command can be recognized in Matplotlib. As a first step, \text can be mapped to \mathdefault, but the amsmath \text command keeps spaces in the given text while \mathdefault does not.

[oscargus]

Another issue here (which is maybe more a theoretical issue maybe) is that \text is supposed to use the text font, not the math font. However, I guess it is most commonly used to obtain upright text in math, rather than using the actual text font in equations. At least in the matplotlib context it seems like a fair approximation.

(One should really need \mathup or something similar to have a family independent, upright font in math mode.)