René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Alpha parameter doesn't work in bar3d","articleBody":"\u003c!--To help us understand and resolve your issue, please fill out the form to the best of your ability.--\u003e\r\n\u003c!--You can feel free to delete the sections that do not apply.--\u003e\r\n\r\n### Bug report\r\n\r\nI have the same problem than on this [Stackoverflow webpage](https://stackoverflow.com/questions/43670867/matplotlib-alpha-transparency-parameter-doesnt-work) : \r\n\r\n\u003c!--A short 1-2 sentences that succinctly describes the bug--\u003e\r\n\r\n**Code for reproduction**\r\n\r\n\u003c!--A minimum code snippet required to reproduce the bug, also minimizing the number of dependencies required--\u003e\r\n\r\n```python\r\nfrom mpl_toolkits.mplot3d import Axes3D\r\nimport numpy as np\r\nimport matplotlib.pyplot as plt\r\n\r\ndef main():\r\n\tplt.ion()\r\n\trho = np.random.random((4,4))\r\n\txpos = np.arange(0,4,1)\r\n\typos = np.arange(0,4,1)\r\n\txpos, ypos = np.meshgrid(xpos, ypos)\r\n\txpos = xpos.flatten()\r\n\typos = ypos.flatten()\r\n\tzpos = np.zeros(4*4)\r\n\tdx = 0.5 * np.ones_like(zpos)\r\n\tdy = dx.copy()\r\n\tdz = rho.flatten()\r\n\talpha = 0.5\r\n\tfig = plt.figure()\r\n\tax = fig.gca(projection='3d')\r\n\tax.bar3d(xpos,ypos,zpos, dx, dy, dz, alpha=alpha, linewidth=0)\r\n\tplt.show()\r\n\tinput(\"Press Enter to continue...\")\r\n\r\nif __name__ == '__main__':\r\n\tmain()\r\n\r\n```\r\n\r\n**Actual outcome**\r\n\r\n\u003c!--The output produced by the above code, which may be a screenshot, console output, etc.--\u003e\r\n\r\nThe bar on the plot are not transparent at all but they should be.\r\n\r\n\u003c!--A description of the expected outcome from the code snippet--\u003e\r\n\u003c!--If this used to work in an earlier version of Matplotlib, please note the version it used to work on--\u003e\r\n\r\n**Matplotlib version**\r\n\u003c!--Please specify your platform and versions of the relevant libraries you are using:--\u003e\r\n  * Operating system: Ubuntu 16.04\r\n  * Matplotlib version: 2.0.2\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): Qt5Agg\r\n  * Python version: 3.6\r\n\r\nMatplotlib have been installerd from conda.\r\n\r\n\u003c!--Please tell us how you installed matplotlib and python e.g., from source, pip, conda--\u003e\r\n\u003c!--If you installed from conda, please specify which channel you used if not the default--\u003e\r\n\r\n","author":{"url":"https://github.com/ngonthier","@type":"Person","name":"ngonthier"},"datePublished":"2017-10-24T15:36:32.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":16},"url":"https://github.com/9559/matplotlib/issues/9559"}