René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Patch3DCollection doesn't update color after calling set_color","articleBody":"I've run into an issue in 1.3.1 and the latest nightly build of the 1.4.x release candidate where calling `set_color` on a Patch3DCollection object doesn't seem to work.  I only see the issue when using a 3D plot.\n\nThis bug was first reported [here](https://github.com/matplotlib/matplotlib/issues/3362), but it seems to be unrelated.\n\nBelow is a snippet similar to what I've been trying. You can comment the lines at the bottom to alternate which version (2d or 3d) you're testing. The same mechanism works for a 2d scatter plot, but not for a 3d one.\n\nThe goal is to add a new point on each animation. Then, change all older points to a different color. It's not optimal and will constantly change the color of old points even if they've already been changed. However, it clearly demonstrates that the call to set_color doesn't have any effect even though it's a somewhat silly example.\n\n``` python\nfrom mpl_toolkits.mplot3d import Axes3D\nimport matplotlib.animation as animation\nimport matplotlib.pylab as plt\n\nimport numpy as np\n\nNUM_POINTS = 10\nvalues = []\n\nfor ii in xrange(NUM_POINTS):\n    values.append(np.random.random_integers(0, 500, 3))\n\npoints = []\n\nn = 0\n\n\ndef two_dim_example():\n    def animate(i):\n        \"\"\"\n        Goal is to slowly add new points and have the most current point in red\n        while all other points are gray\n        \"\"\"\n\n        global n\n\n        # No more animation needed\n        if n \u003e= NUM_POINTS:\n            return\n\n        # Change color of all old points\n        for point in points:\n            point.set_color('gray')\n\n        x, y, z = values[n]\n\n        point = ax2D.scatter(x, y, s=75, c='red', marker ='o')\n        points.append(point)\n\n        n += 1\n\n    ax2D = fig1.add_subplot(111)\n    ani = animation.FuncAnimation(fig1, animate, interval=500)\n    plt.show()\n\n\ndef three_dim_example():\n    def animate(i):\n        \"\"\"\n        Goal is to slowly add new points and have the most current point in red\n        while all other points are gray\n        \"\"\"\n\n        global n\n\n        # No more animation needed\n        if n \u003e= NUM_POINTS:\n            return\n\n        # Change color of all old points\n        for point in points:\n            point.set_color('gray')\n\n        x, y, z = values[n]\n\n        point = ax3D.scatter(x, y, z, s=50, c='red', marker ='o')\n        points.append(point)\n\n        n += 1\n\n    ax3D = fig2.add_subplot(111, projection='3d')\n    ani = animation.FuncAnimation(fig2, animate, interval=500)\n    plt.show()\n\n\n# Uncomment to see that 2d works\n#fig1 = plt.figure()\n#two_dim_example()\n\nfig2 = plt.figure()\nthree_dim_example()\n```\n","author":{"url":"https://github.com/durden","@type":"Person","name":"durden"},"datePublished":"2014-08-15T13:45:42.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":8},"url":"https://github.com/3370/matplotlib/issues/3370"}