René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Extra Grid Line On Plot (PyPlot)","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\n**Bug summary**\r\n\r\n\u003c!--A short 1-2 sentences that succinctly describes the bug--\u003e\r\n\r\nWhen changing the color of major gridlines in a plot, some major grid lines will occasionally have a gray, slightly transparent line placed over it.\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\n# Paste your code here\r\n#\r\n#\r\nimport numpy as np\r\nimport matplotlib.pyplot as plt\r\n\r\naX = np.array([4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24])\t\t\t# x-axis\r\naY = np.array([1,4,10,20,35,56,80,104,125,140,146,140,125,104,80,56,35,20,10,4,1])\t# y-axis\r\naY = aY / aY.sum()\r\n\r\nplt.plot(aX, aY)\t\t\t\t\t\t\t\t\t\t\t\t\t\t# plot curve and show\r\n\r\nplt.xlim((0, 30))\r\nplt.ylim(ymin = 0)\r\nplt.grid(True, 'major', color='k')\r\nplt.minorticks_on()\r\nplt.grid(True, 'minor', 'y')\r\nplt.show()\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\n![image](https://user-images.githubusercontent.com/1453972/43102068-bb368710-8e8f-11e8-901d-b8a6e100fa99.png)\r\n\r\nNote the major grid line at 0.06 seems to be \"shaded over\".  Additionally, this issue doesn't happen if `aY = aY / aY.sum()` is commented out.\r\n\r\n```\r\n# If applicable, paste the console output here\r\n#\r\n#\r\n```\r\n\r\n**Expected outcome**\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\nI would expect that all major grid lines have the color specified by `plt.grid(True, 'major', color='k')`.\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: Windows 7 Professional 64bit\r\n  * Matplotlib version: 2.2.2\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): TkAgg\r\n  * Python version: 3.6.2\r\n  * Jupyter version (if applicable): N/A\r\n  * Other libraries: numpy\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\nI installed python from the available .exe file.  I installed matplotlib according to the instructions on the website (with pip).\r\n\r\n","author":{"url":"https://github.com/skitko","@type":"Person","name":"skitko"},"datePublished":"2018-07-23T20:54:23.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/11758/matplotlib/issues/11758"}