René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: LogLocator with subs argument fragile.","articleBody":"### Bug summary\r\n\r\nLogarithmic tick markers do not appear if the y-axis scales a sufficient range, with the `subs` keyword argument of `ticker.LogLocator` set to non-trivial values.\r\n\r\n\r\n### Code for reproduction\r\n\r\n```python\r\nimport matplotlib.pyplot as plt\r\nimport matplotlib.ticker\r\nimport numpy as np\r\n\r\nll = matplotlib.ticker.LogLocator(subs=(1, 2, 5))\r\n\r\n### The following code produces a plot with y-axis ticks at the expected locations.\r\n\r\nfig, ax = plt.subplots()\r\nx = np.arange(8)\r\nplt.semilogy(x, 10 ** x)\r\nax.yaxis.set_major_locator(ll)\r\nax.yaxis.set_minor_locator(ll)\r\nplt.title(\"Good Plot\")\r\nplt.show()\r\n\r\n### The following code produces a plot with no y-axis ticks, which is unexpected and undesired.\r\n\r\nfig, ax = plt.subplots()\r\nx = np.arange(9)  # The only change is this line\r\nplt.semilogy(x, 10 ** x)\r\nax.yaxis.set_major_locator(ll)\r\nax.yaxis.set_minor_locator(ll)\r\nplt.title(\"Bad Plot\")\r\nplt.show()\r\n\r\n### The problem is isolated to here, which returns correct values in the first case, but np.array([]) in the second case:\r\nprint(ll.tick_values(1, 1e7))\r\nprint(ll.tick_values(1, 1e8))\r\n```\r\n\r\n\r\n### Actual outcome\r\n\r\n![image](https://user-images.githubusercontent.com/6295985/193890350-8914dcd1-af5a-4466-9e43-b21396352a56.png)\r\n\r\n![image](https://user-images.githubusercontent.com/6295985/193890374-0f9c1f65-e89a-40b1-a095-2367b68a39fd.png)\r\n\r\n\r\n\r\n### Expected outcome\r\n\r\nI expect to see ticks in both cases, as appears in the \"Good Plot\".\r\n\r\n### Additional information\r\n\r\nThe problem is isolated to `ticker.LogLocator.tick_values()`. This returns correct values in the first case (e.g., `np.array([1.e-01 2.e-01 5.e-01 1.e+00 2.e+00 5.e+00 1.e+01 2.e+01 5.e+01 1.e+02\r\n 2.e+02 5.e+02])`), but `np.array([])` in the second case.\r\n\r\n### Operating system\r\n\r\nWindows\r\n\r\n### Matplotlib Version\r\n\r\n3.5.2\r\n\r\n### Matplotlib Backend\r\n\r\nmodule://backend_interagg\r\n\r\n### Python version\r\n\r\n3.9.13\r\n\r\n### Jupyter version\r\n\r\n_No response_\r\n\r\n### Installation\r\n\r\nconda","author":{"url":"https://github.com/peterdsharpe","@type":"Person","name":"peterdsharpe"},"datePublished":"2022-10-04T17:52:52.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":9},"url":"https://github.com/24092/matplotlib/issues/24092"}