René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Radial grid missing in polar plots with ax.set_theta_direction(-1) and ax.set_theta_zero_location","articleBody":"When creating a polar plot with inverted theta direction and modifying the location of zero, the radial grid and outer boundary are missing for some locations of zero.\r\n\r\n```python\r\nimport numpy as np\r\nimport matplotlib.pyplot as plt\r\n\r\nr = np.arange(0, 2, 0.01)\r\ntheta = 2 * np.pi * r\r\n\r\nfig, ax = plt.subplots(subplot_kw={'projection': 'polar'})\r\nax.plot(theta, r)\r\n\r\nax.set_theta_direction(-1)\r\n\r\nangle = 10 # 20 is not working, 10 is working\r\nax.set_theta_zero_location(\"N\",angle) \r\nplt.savefig('expected-outcome.png')\r\n\r\nangle = 20 # 20 is not working, 10 is working\r\nax.set_theta_zero_location(\"N\",angle) \r\nplt.savefig('actual-outcome.png')\r\n```\r\nThis is the outcome (can be reproduced with angle=20):\r\n![actual-outcome](https://user-images.githubusercontent.com/29770911/121178497-d4f15980-c85e-11eb-8150-6b8a2f2cd40a.png)\r\n\r\nAnd this is what it should look like (can be reproduced with angle=10):\r\n![expected-outcome](https://user-images.githubusercontent.com/29770911/121178520-da4ea400-c85e-11eb-8e98-6b84e705746f.png)\r\n\r\n```python\r\nimport matplotlib\r\nprint(matplotlib.__version__)\r\nimport platform\r\nprint(platform.python_version())\r\n3.4.2\r\n3.9.2\r\n```\r\n\r\nWhen I go back to matplotlib release v3.2.2 I don't have this issue.\r\n\r\n","author":{"url":"https://github.com/olehy","@type":"Person","name":"olehy"},"datePublished":"2021-06-08T11:45:28.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/20388/matplotlib/issues/20388"}