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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"\"ValueError: All values in the dash list must be positive\" if linewidth is set to zero in matplotlib 2.x.x","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\nIn matplotlib 2.x.x, `ValueError: All values in the dash list must be positive` will be raised if linewidth is set to zero while it seems to work in matplotlib 1.5.x. No idea whether it is a bug or you intend to do so, but my macro don't work anymore because of this...\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\nimport matplotlib.pyplot as plt\r\nx = [0, 1]\r\nplt.plot(x, x, ls = '--', lw = 0)\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- matplotlib 2.0.2\r\n```\r\nTraceback (most recent call last):\r\n  File \"/usr/lib/python2.7/lib-tk/Tkinter.py\", line 1489, in __call__\r\n    return self.func(*args)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/backends/backend_tkagg.py\", line 280, in resize\r\n    self.show()\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/backends/backend_tkagg.py\", line 351, in draw\r\n    FigureCanvasAgg.draw(self)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/backends/backend_agg.py\", line 464, in draw\r\n    self.figure.draw(self.renderer)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/artist.py\", line 63, in draw_wrapper\r\n    draw(artist, renderer, *args, **kwargs)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/figure.py\", line 1144, in draw\r\n    renderer, self, dsu, self.suppressComposite)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/image.py\", line 139, in _draw_list_compositing_images\r\n    a.draw(renderer)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/artist.py\", line 63, in draw_wrapper\r\n    draw(artist, renderer, *args, **kwargs)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/axes/_base.py\", line 2426, in draw\r\n    mimage._draw_list_compositing_images(renderer, self, dsu)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/image.py\", line 139, in _draw_list_compositing_images\r\n    a.draw(renderer)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/artist.py\", line 63, in draw_wrapper\r\n    draw(artist, renderer, *args, **kwargs)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/lines.py\", line 822, in draw\r\n    drawFunc(renderer, gc, tpath, affine.frozen())\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/lines.py\", line 1267, in _draw_lines\r\n    self._lineFunc(renderer, gc, path, trans)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/lines.py\", line 1297, in _draw_dashed\r\n    gc.set_dashes(self._dashOffset, self._dashSeq)\r\n  File \"/home/chenyh/.local/lib/python2.7/site-packages/matplotlib/backend_bases.py\", line 1009, in set_dashes\r\n    raise ValueError(\"All values in the dash list must be positive\")\r\nValueError: All values in the dash list must be positive\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\n- matplotlib1.5.1\r\n![figure_1](https://user-images.githubusercontent.com/10009214/27688159-df8dc3a0-5cd9-11e7-80c5-f029a46b777c.png)\r\n\r\n\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: Tested on both Ubuntu 14.04.5 LTS / Mac OS X 10.12.5\r\n  * Matplotlib Version: 2.0.2\r\n  * Python Version: 2.7.13\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/Awen0121","@type":"Person","name":"Awen0121"},"datePublished":"2017-06-29T12:54:07.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/8821/matplotlib/issues/8821"}