René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Issue when setting scatter color in separate method call","articleBody":"For an application I am developing, I need to call ``ax.scatter`` then change the colors of the points after the fact. However, if the input x/y values contain NaN values, then setting the colors after the fact doesn't work properly. The following example:\r\n\r\n```python\r\nimport matplotlib\r\nmatplotlib.use('Agg')\r\n\r\nimport numpy as np\r\nimport matplotlib.pyplot as plt\r\n\r\nfig = plt.figure()\r\nax = fig.add_subplot(1, 1, 1, aspect='auto')\r\n\r\nx = np.array([1, 2, 3])\r\ny = np.array([2, np.nan, 4])\r\nc = np.array([3, 4, 5])\r\n\r\ns = ax.scatter(x, y, c=c, vmin=3, vmax=5, s=320, zorder=1, edgecolor='none')\r\n\r\ns = ax.scatter(x, y, s=160, zorder=2, edgecolor='none')\r\ns.set_array(c)\r\ns.set_clim(3, 5)\r\n\r\ns = ax.scatter([], [], s=40, zorder=3, edgecolor='none')\r\ns.set_offsets(np.vstack([x, y]).transpose())\r\ns.set_array(c)\r\ns.set_clim(3, 5)\r\n\r\nfig.savefig('test.png')\r\n\r\n```\r\n\r\nproduces the following output:\r\n\r\n![test](https://user-images.githubusercontent.com/314716/35814346-bdb682f0-0a8d-11e8-846e-07b7a9120827.png)\r\n\r\nThe top right point should be all yellow. However it isn't, because in the ``scatter`` call, invalid values are removed, so when I try and set the colors with ``set_array``, the color values are offset from the x/y values. In the final case, things work since the 'bad' values are masked from neither the offsets nor the colors.\r\n\r\nIs there a way to achieve something along the lines of the middle example (setting the colors after the fact)","author":{"url":"https://github.com/astrofrog","@type":"Person","name":"astrofrog"},"datePublished":"2018-02-05T16:02:47.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/10381/matplotlib/issues/10381"}