René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Issues with autoscaling and transforms with 3.2+","articleBody":"### Bug report\r\n\r\n**Bug summary**\r\n\r\nI am encountering a few seemingly related issues but can't exactly define what's happening. They broadly relate to unexpected changes in how plots are scaled and appear in the context of using the transform objects attached to the Axes. I assume they are caused by changes in autoscaling in 3.2, but don't know whether they are a bug or if previous code was relying on undefined behavior (the release notes are a little vague about what actually changed).\r\n\r\n**Code for reproduction**\r\n\r\nHere is a simple example derived from an issue in seaborn rugplot (https://github.com/mwaskom/seaborn/issues/2015)\r\n\r\n```python\r\nimport numpy as np\r\nimport matplotlib as mpl\r\nimport matplotlib.transforms as tx\r\nfrom matplotlib.collections import LineCollection\r\nimport matplotlib.pyplot as plt\r\n\r\na = [1, 2, 4]\r\nheight = .2\r\n\r\nxy_pairs = np.column_stack([np.repeat(a, 2), np.tile([0, height], len(a))])\r\nline_segs = xy_pairs.reshape([len(a), 2, 2])\r\n\r\nf, ax = plt.subplots()\r\ntrans = tx.blended_transform_factory(ax.transData, ax.transAxes)\r\nax.add_collection(LineCollection(line_segs, transform=trans))\r\nax.autoscale_view(scalex=True, scaley=False)\r\n```\r\n\r\n**Actual outcome**\r\n\r\nWith matplotlib 3.2.1:\r\n\r\n![image](https://user-images.githubusercontent.com/315810/78386922-74a4bf00-75ac-11ea-8021-dff6478c85aa.png)\r\n\r\n**Expected outcome**\r\n\r\nWith matplotlib 3.1.2:\r\n\r\n![image](https://user-images.githubusercontent.com/315810/78386970-87b78f00-75ac-11ea-89d3-84239e0bf8b5.png)\r\n\r\n\r\n**Matplotlib version**\r\n\r\n  * Operating system: macos\r\n  * Matplotlib version: 3.2.1\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): ipython inline\r\n\r\n**Other information**\r\n\r\nLinking another seaborn issue (https://github.com/mwaskom/seaborn/issues/2013) where there has been a similar change in behavior with matplotlib 3.2 but where it's harder to extract a standalone issue.","author":{"url":"https://github.com/mwaskom","@type":"Person","name":"mwaskom"},"datePublished":"2020-04-03T17:14:03.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/17016/matplotlib/issues/17016"}