René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"scatter() should not drop data points at nonfinite coordinates","articleBody":"Currently, scatter() completely drops data points at nonfinite coordinates from the PathCollection it builds:\r\n```\r\nfig, ax = plt.subplots()\r\nx = [0, 1, np.nan, 3]\r\ny = [0, 1, 2, 3]\r\nc = [0, 1, 2, 3]\r\npc = ax.scatter(x, y, c=c)\r\nprint(pc.get_offsets())\r\n```\r\nresults in\r\n```\r\n[[0. 0.]\r\n [1. 1.]\r\n [3. 3.]]\r\n```\r\ni.e. the [2, nan] point is not recorded anywhere, even though **we could just as well keep track of it and let the *renderer* do the job of not rendering nonfinite points**.\r\n\r\nAs a result, this makes event picking less-than-optimal: adding\r\n```\r\nfig.canvas.mpl_connect(\"button_press_event\", lambda event: print(pc.contains(event)))\r\n```\r\nto the code above, one sees that the first point is picked at index 0 (`(True, {'ind': array([0], dtype=int32)})` is printed when clicking on it), the second one at index 1, and the last one at index 2.  So one cannot use the resulting index to lookup into `x`/`y`/`c`, one has to index into `pc.get_offsets()`/`pc.get_array()`; and if one wants to index into some *other* array (my actual use case), one needs to manually count the nans in `x`/`y`/`c` and do the index conversion.\r\nAs a comparison point, `Line2D` does keep invalid points around and lets the renderer kill them.\r\n\r\nLikewise, points with nonfinite values are dropped:\r\n```\r\npc = ax.scatter([0, 1, 2, 3], [0, 1, 2, 3], c=[0, np.nan, np.inf, 1])\r\n```\r\nresults in behavior similar to the one described above.\r\nIn this specific case, I actually think nonfinite points should respect the colormap's colors set by `set_under`/`set_over`/`set_bad` (right now they don't, they are again wiped out of existence) -- after all that's exactly what these \"extra\" colors are for.\r\n\r\nThis second issue (invalid `c`) has already been reported elsewhere and there are already PRs for it: #4354/#9891/#12422.\r\n\r\nmpl master/3.0.2\r\nArch Linux/Py3.7","author":{"url":"https://github.com/anntzer","@type":"Person","name":"anntzer"},"datePublished":"2018-11-12T22:31:53.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/12801/matplotlib/issues/12801"}