René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: set linestyle='dashed' raise error with quiver and legend","articleBody":"### Bug summary\n\nIssue description:\r\nI am trying to print the linear arrow with dashed style, but there is error waring \r\n\"ValueError: At least one value in the dash list must be positive\"\r\n\r\nCode: \r\nPart Code like following\r\nplt.quiver(0, 0, v1[0], v1[1], angles='xy', scale_units='xy', scale=1, color='r', label='v1 (3, 4)', linestyle='solid')\r\nplt.quiver(0, 0, v2[0], v2[1], angles='xy', scale_units='xy', scale=1, color='b', label='v2 (4, -3)', linestyle='solid')\r\nv_sum = v1 + v2\r\nplt.quiver(0, 0, v_sum[0], v_sum[1], angles='xy', scale_units='xy', scale=1, color='g', linestyle='dashed', linewidth=0, label='v1 + v2')\r\n\r\n#I searched similar issue ticket: https://github.com/matplotlib/matplotlib/issues/8821 to set lw=0, it's still not work\r\n\r\nenviroment:\r\nmy python version: Python 3.12.3\r\nmatplotlib version:      3.9.0\r\n\n\n### Code for reproduction\n\n```Python\nplt.quiver(0, 0, v1[0], v1[1], angles='xy', scale_units='xy', scale=1, color='r', label='v1 (3, 4)', linestyle='solid')\r\nplt.quiver(0, 0, v2[0], v2[1], angles='xy', scale_units='xy', scale=1, color='b', label='v2 (4, -3)', linestyle='solid')\r\nv_sum = v1 + v2\r\nplt.quiver(0, 0, v_sum[0], v_sum[1], angles='xy', scale_units='xy', scale=1, color='g', linestyle='dashed', linewidth=0, label='v1 + v2')\n```\n\n\n### Actual outcome\n\nThere is empty present \r\n![image](https://github.com/matplotlib/matplotlib/assets/117837983/eec366de-8b7d-4647-85e3-5da92bce1566)\r\n\r\n\r\n(mathenv) C:\\WorkSpace\\math\u003ec:/WorkSpace/math/mathenv/Scripts/python.exe c:/WorkSpace/math/linearAnalog.py\r\nException in Tkinter callback\r\nTraceback (most recent call last):\r\n  File \"C:\\Python312\\Lib\\tkinter\\__init__.py\", line 1967, in __call__\r\n    return self.func(*args)\r\n           ^^^^^^^^^^^^^^^^\r\n  File \"C:\\Python312\\Lib\\tkinter\\__init__.py\", line 861, in callit\r\n    func(*args)\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\backends\\_backend_tk.py\", line 271, in idle_draw\r\n    self.draw()\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\backends\\backend_tkagg.py\", line 10, in draw\r\n    super().draw()\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\backends\\backend_agg.py\", line 387, in draw\r\n    self.figure.draw(self.renderer)\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\artist.py\", line 95, in draw_wrapper\r\n    result = draw(artist, renderer, *args, **kwargs)\r\n             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\artist.py\", line 72, in draw_wrapper\r\n    return draw(artist, renderer)\r\n           ^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\figure.py\", line 3155, in draw\r\n    mimage._draw_list_compositing_images(\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\image.py\", line 132, in _draw_list_compositing_images\r\n    a.draw(renderer)\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\artist.py\", line 72, in draw_wrapper\r\n    return draw(artist, renderer)\r\n           ^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\axes\\_base.py\", line 3109, in draw\r\n    mimage._draw_list_compositing_images(\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\image.py\", line 132, in _draw_list_compositing_images\r\n    a.draw(renderer)\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\artist.py\", line 72, in draw_wrapper\r\n    return draw(artist, renderer)\r\n           ^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\legend.py\", line 777, in draw\r\n    self._legend_box.draw(renderer)\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\artist.py\", line 39, in draw_wrapper\r\n    return draw(artist, renderer, *args, **kwargs)\r\n           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\offsetbox.py\", line 383, in draw\r\n    c.draw(renderer)\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\artist.py\", line 39, in draw_wrapper\r\n    return draw(artist, renderer, *args, **kwargs)\r\n           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\offsetbox.py\", line 383, in draw\r\n    c.draw(renderer)\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\artist.py\", line 39, in draw_wrapper\r\n    return draw(artist, renderer, *args, **kwargs)\r\n           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\offsetbox.py\", line 383, in draw\r\n    c.draw(renderer)\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\artist.py\", line 39, in draw_wrapper\r\n    return draw(artist, renderer, *args, **kwargs)\r\n           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\offsetbox.py\", line 383, in draw\r\n    c.draw(renderer)\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\artist.py\", line 39, in draw_wrapper\r\n    return draw(artist, renderer, *args, **kwargs)\r\n           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\offsetbox.py\", line 669, in draw\r\n    c.draw(renderer)\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\artist.py\", line 72, in draw_wrapper\r\n    return draw(artist, renderer)\r\n           ^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\patches.py\", line 632, in draw\r\n    self._draw_paths_with_artist_properties(\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\patches.py\", line 594, in _draw_paths_with_artist_properties\r\n    gc.set_dashes(*self._dash_pattern)\r\n  File \"c:\\WorkSpace\\math\\mathenv\\Lib\\site-packages\\matplotlib\\backend_bases.py\", line 924, in set_dashes\r\n    raise ValueError(\r\nValueError: At least one value in the dash list must be positive\n\n### Expected outcome\n\nExpect the plt.quiver can print a dash arrow for the sum of two linear array\n\n### Additional information\n\n_No response_\n\n### Operating system\n\n_No response_\n\n### Matplotlib Version\n\n3.9.0\n\n### Matplotlib Backend\n\n_No response_\n\n### Python version\n\n_No response_\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\nNone","author":{"url":"https://github.com/quzhijing","@type":"Person","name":"quzhijing"},"datePublished":"2024-05-25T17:41:48.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":8},"url":"https://github.com/28298/matplotlib/issues/28298"}