René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"contour and contourf treat levels differently","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\nWhen setting levels that span a wider range of values than the data set, contourf correctly picks the right  colors to fill the areas between the contour lines. contour does not use the same colors.\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\nimport numpy as np\r\nimport matplotlib.pyplot as plt\r\n\r\nlevels = np.arange(-100, 100, 10)\r\n\r\nx = np.loadtxt(open('x.txt','rb'),delimiter=',')\r\ny = np.loadtxt(open('y.txt','rb'),delimiter=',')\r\nz = np.loadtxt(open('z.txt','rb'),delimiter=',')\r\n\r\n#CS = plt.contour(x, y, z, levels)\r\nCS = plt.contourf(x, y, z, levels)\r\n\r\nCB = plt.colorbar(CS)\r\n\r\nplt.show()\r\n```\r\n\r\nThe data is attached.\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\nWhen plotting with contour instead of contourf the colors range is scaled according to the maximum and minimum of the used data.\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 contour to respect the range set in levels.\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: Debian unstable\r\n  * Matplotlib version: 2.1.1-2\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): TkAgg\r\n  * Python version: \r\n  * Jupyter version (if applicable):\r\n  * Other libraries: \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[z.txt](https://github.com/matplotlib/matplotlib/files/1750666/z.txt)\r\n[y.txt](https://github.com/matplotlib/matplotlib/files/1750667/y.txt)\r\n[x.txt](https://github.com/matplotlib/matplotlib/files/1750668/x.txt)\r\n\r\nInstalled from Debian package","author":{"url":"https://github.com/boeleman","@type":"Person","name":"boeleman"},"datePublished":"2018-02-23T06:37:35.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/10572/matplotlib/issues/10572"}