René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Noninteger Bases in mathtext sqrt","articleBody":"### Bug report\r\n\r\n**Bug summary**\r\nIt appears that only integer sqrt bases are allowed by mathtext. The documentation does not list this limitation.\r\n\r\n**Code for reproduction**\r\n```\r\nimport matplotlib.pyplot as plt\r\n\r\nfig = plt.figure()\r\naxis = fig.add_subplot(1, 1, 1)\r\naxis.plot(1, 1, label=r'$\\sqrt[a]{{x}}$')\r\naxis.legend()\r\nplt.show()\r\n```\r\n\r\n**Actual outcome**\r\n`mathtext.Parser.parse` raises a `ValueError`.\r\n\r\n**Expected outcome**\r\nThe [documentation](https://matplotlib.org/users/mathtext.html#radicals) states the following:\r\n\r\n\u003e Radicals can be produced with the \\sqrt[]{} command ... Any base can (optionally) be provided inside square brackets. Note that the base must be a simple expression, and can not contain layout commands such as fractions or sub/superscripts\r\n\r\nIn fact, it seems that only a (signed) integer literal is allowed. From `mathtext.Parser.__init__`:\r\n```\r\np.sqrt          \u003c\u003c= Group(\r\n                     Suppress(Literal(r\"\\sqrt\"))\r\n                   - ((Optional(p.lbracket + p.int_literal + p.rbracket, default=None)\r\n                      + p.required_group)\r\n                   | Error(\"Expected \\sqrt{value}\"))\r\n                 )\r\n```\r\nIt would be convenient if other bases were allowed. If that change cannot be made (or in the meantime), I think the documentation should be updated.\r\n\r\n**Matplotlib version**\r\n  * Operating System: Debian 9.0\r\n  * Matplotlib Version: 2.0.0\r\n  * Python Version: 3.5.3\r\n\r\nI believe I installed Python from the `python3.5` package in the `stretch` repository and Matplotlib from the `python3-matplotlib` package in the `stretch` repository, but I'm not sure.","author":{"url":"https://github.com/ben-e-whitney","@type":"Person","name":"ben-e-whitney"},"datePublished":"2017-05-25T23:18:50.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/8665/matplotlib/issues/8665"}