René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: Unkown symbol in $..$ when text.usetex: False ","articleBody":"### Bug summary\n\nPlacing non-standard tex commands like \\unit{mm} from siunitx package on  $...$ when used for labels (and probably other text elements)  does not work when tex rendering by matplotlib is **disabled**.\r\nDoes it still check stuff in $ signs for valid commands? \r\n\r\n\n\n### Code for reproduction\n\n```python\nimport locale\r\nimport matplotlib\r\nimport matplotlib.pyplot as plt\r\n\r\nmatplotlib.use('TkAgg')\r\nplt.style.use('matplotlib_style.mplstyle')  \r\n# text.usetex: False \r\n# text.latex.preamble:  r'\\usepackage{amsmath}\\usepackage{siunitx}'\r\nlocale.setlocale(locale.LC_ALL, '')\r\n\r\nfig, ax = plt.subplots()\r\nax.plot([0], [0], 'x')\r\n\r\nax.set_xlabel(r'$\\Delta x$ \\unit{mm}')  # \u003c- does work\r\nax.set_xlabel(r'$\\Delta x \\unit{mm}$')  # \u003c- does not work \r\nplt.savefig('fig.svg')  # plt.show() does not work either\n```\n\n\n### Actual outcome\n\nTraceback (most recent call last):\r\n  File \"/venv/lib/python3.10/site-packages/matplotlib/_mathtext.py\", line 2237, in parse\r\n    result = self._expression.parseString(s)\r\n  File \"/venv/lib/python3.10/site-packages/pyparsing/core.py\", line 1134, in parse_string\r\n    raise exc.with_traceback(None)\r\npyparsing.exceptions.ParseFatalException: Unknown symbol: \\unit, found '\\'  (at char 0), (line:1, col:1)\r\n\r\n...\r\n\r\nValueError: \r\n\\unit{mm}\r\n^\r\nUnknown symbol: \\unit, found '\\'  (at char 0), (line:1, col:1)\r\n\n\n### Expected outcome\n\nLabel with plain text (not Tex rendered yet) text in .svg file \r\n(rendering those later with latex svg package)\n\n### Additional information\n\nSeems to happen when non standard commands are used in math mode (like $\\unit{mm}$)\r\nBoth $\\unit{mm}$ and \\unit{mm} work with siunitx package and xetex\n\n### Operating system\n\nPopOS 21.10\n\n### Matplotlib Version\n\n3.5.1\n\n### Matplotlib Backend\n\nTkAgg\n\n### Python version\n\n3.10.0 | Make \"In console: python --version or python3 --version\" in bug report form\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\npip","author":{"url":"https://github.com/Nikongen","@type":"Person","name":"Nikongen"},"datePublished":"2022-02-22T23:17:01.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/22537/matplotlib/issues/22537"}