René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Lines are not affected by changing polar limits after draw","articleBody":"From #12300, something funny happens if you flip the radial limits after a draw. @jklymak noted that this is also a problem on current `master` if you just change the limits (but no flipping.)\r\n\r\n```python\r\n#!/usr/bin/env python\r\n\r\nimport numpy as np\r\nimport matplotlib.pyplot as plt\r\n\r\nfig, (ax0, ax1, ax2) = plt.subplots(1, 3, subplot_kw=dict(polar=True))\r\n\r\nax0.plot([0, 1], [-1, 1])\r\nax0.scatter([0, 1], [-1, 1])\r\n\r\nax0.set_rmin(-1.5)\r\nax0.set_rmax(1.5)\r\nax0.set_title('Forward')\r\n\r\nax1.plot([0, 1], [-1, 1])\r\nax1.scatter([0, 1], [-1, 1])\r\n\r\nax1.set_rmin(1.5)\r\nax1.set_rmax(-1.5)\r\nax1.set_title('Backward')\r\n\r\nax2.plot([0, 1], [-1, 1])\r\nax2.scatter([0, 1], [-1, 1])\r\n\r\nax2.set_rmin(-1.5)\r\nax2.set_rmax(1.5)\r\nax2.set_title('Backward with draw')\r\nfig.canvas.draw()\r\nax2.set_rmin(1.5)\r\nax2.set_rmax(-1.5)\r\n\r\nplt.show()\r\n```\r\n![figure_1](https://user-images.githubusercontent.com/302469/48756087-b35f0100-ec65-11e8-82c6-8e30dd0fb336.png)\r\n\r\n_Originally posted by @QuLogic in https://github.com/matplotlib/matplotlib/pull/12300#issuecomment-440162352_","author":{"url":"https://github.com/QuLogic","@type":"Person","name":"QuLogic"},"datePublished":"2018-11-26T00:23:23.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/12887/matplotlib/issues/12887"}