René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Axes3D scatter crashes without alpha keyword","articleBody":"version: 2.0.0b1+1773.g3590ce2\nbackend: gtkagg inside an ipython session\n\ncode snippet is:\n\n``` python\nfrom mpl_toolkits.mplot3d import Axes3D\nclf()\nax = subplot(111, projection='3d')\nl1 = ax.scatter([0,0.01,1],[0,0.01,1],[0,0.01,1], c='b')\n# asc is a 93,3 numpy array of float128\n# if required I can supply this data. \nQ = zip(*asc)\nl2 = ax.scatter(Q[0],Q[1],Q[2], c='b')\n#l2.set_alpha(0.5)\ndraw()\n```\n\nif alpha is not set for l2, then we crash. Visually there's lots of overlap in the l2 marker points. Notably l1 doesn't crash even without an alpha parameter, even though I do see overlap in the two close marker points.\n\n``` pytb\nTraceback (most recent call last):\n  File \"/Users/mcj/lib/python2.7/site-packages/matplotlib-2.0.0b1+1773.g3590ce2-py2.7-macosx-10.11-x86_64.egg/matplotlib/backends/backend_gtk.py\", line 443, in expose_event\n    self._render_figure(self._pixmap, w, h)\n  File \"/Users/mcj/lib/python2.7/site-packages/matplotlib-2.0.0b1+1773.g3590ce2-py2.7-macosx-10.11-x86_64.egg/matplotlib/backends/backend_gtkagg.py\", line 87, in _render_figure\n    FigureCanvasAgg.draw(self)\n  File \"/Users/mcj/lib/python2.7/site-packages/matplotlib-2.0.0b1+1773.g3590ce2-py2.7-macosx-10.11-x86_64.egg/matplotlib/backends/backend_agg.py\", line 464, in draw\n    self.figure.draw(self.renderer)\n  File \"/Users/mcj/lib/python2.7/site-packages/matplotlib-2.0.0b1+1773.g3590ce2-py2.7-macosx-10.11-x86_64.egg/matplotlib/artist.py\", line 68, in draw_wrapper\n    return draw(artist, renderer, *args, **kwargs)\n  File \"/Users/mcj/lib/python2.7/site-packages/matplotlib-2.0.0b1+1773.g3590ce2-py2.7-macosx-10.11-x86_64.egg/matplotlib/figure.py\", line 1262, in draw\n    renderer, self, dsu, self.suppressComposite)\n  File \"/Users/mcj/lib/python2.7/site-packages/matplotlib-2.0.0b1+1773.g3590ce2-py2.7-macosx-10.11-x86_64.egg/matplotlib/image.py\", line 139, in _draw_list_compositing_images\n    a.draw(renderer)\n  File \"/Users/mcj/lib/python2.7/site-packages/matplotlib-2.0.0b1+1773.g3590ce2-py2.7-macosx-10.11-x86_64.egg/mpl_toolkits/mplot3d/axes3d.py\", line 272, in draw\n    for col in self.collections]\n  File \"/Users/mcj/lib/python2.7/site-packages/matplotlib-2.0.0b1+1773.g3590ce2-py2.7-macosx-10.11-x86_64.egg/mpl_toolkits/mplot3d/art3d.py\", line 460, in do_3d_projection\n    fcs = mcolors.to_rgba_array(fcs, self._alpha)\n  File \"/Users/mcj/lib/python2.7/site-packages/matplotlib-2.0.0b1+1773.g3590ce2-py2.7-macosx-10.11-x86_64.egg/matplotlib/colors.py\", line 227, in to_rgba_array\n    result[i] = to_rgba(cc, alpha)\n  File \"/Users/mcj/lib/python2.7/site-packages/matplotlib-2.0.0b1+1773.g3590ce2-py2.7-macosx-10.11-x86_64.egg/matplotlib/colors.py\", line 134, in to_rgba\n    rgba = _to_rgba_no_colorcycle(c, alpha)\n  File \"/Users/mcj/lib/python2.7/site-packages/matplotlib-2.0.0b1+1773.g3590ce2-py2.7-macosx-10.11-x86_64.egg/matplotlib/colors.py\", line 192, in _to_rgba_no_colorcycle\n    raise ValueError(\"RGBA values should be within 0-1 range\")\nValueError: RGBA values should be within 0-1 range\n```\n","author":{"url":"https://github.com/kaufman","@type":"Person","name":"kaufman"},"datePublished":"2016-07-06T17:05:55.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/6698/matplotlib/issues/6698"}