René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"plt.scatter, error with NaN values and edge color","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\nWhen plotting a `scatter` plot with y containing NaN values, depending on the number of values, an error comes up when setting the `color` or `edgecolor`.\r\nThis error was introduced with version 3.3.0, might be linked to  #17849\r\n\u003c!--A short 1-2 sentences that succinctly describes the bug--\u003e\r\n\r\n**Code for reproduction**\r\nHere is a basic example\r\n\u003c!--A minimum code snippet required to reproduce the bug.\r\nPlease make sure to minimize the number of dependencies required, and provide\r\nany necessary plotted data.\r\nAvoid using threads, as Matplotlib is (explicitly) not thread-safe.--\u003e\r\n\r\n```python\r\nimport matplotlib.pyplot as plt\r\nimport numpy as np\r\nplt.scatter([1, 2, 3], [ 0, np.nan, 2],color=(1, 0, 0))\r\n```\r\n\r\n**Actual outcome**\r\n\u003c!--The output produced by the above code, which may be a screenshot, console output, etc.--\u003e\r\n```\r\n---------------------------------------------------------------------------\r\nValueError                                Traceback (most recent call last)\r\n\u003cipython-input-77-cf954735eeaf\u003e in \u003cmodule\u003e\r\n      1 import matplotlib.pyplot as plt\r\n      2 import numpy as np\r\n----\u003e 3 plt.scatter([1, 2, 3], [ 0, np.nan, 2],color=(1, 0, 0))\r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/pyplot.py in scatter(x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, verts, edgecolors, plotnonfinite, data, **kwargs)\r\n   2888         verts=cbook.deprecation._deprecated_parameter,\r\n   2889         edgecolors=None, *, plotnonfinite=False, data=None, **kwargs):\r\n-\u003e 2890     __ret = gca().scatter(\r\n   2891         x, y, s=s, c=c, marker=marker, cmap=cmap, norm=norm,\r\n   2892         vmin=vmin, vmax=vmax, alpha=alpha, linewidths=linewidths,\r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/__init__.py in inner(ax, data, *args, **kwargs)\r\n   1445     def inner(ax, *args, data=None, **kwargs):\r\n   1446         if data is None:\r\n-\u003e 1447             return func(ax, *map(sanitize_sequence, args), **kwargs)\r\n   1448 \r\n   1449         bound = new_sig.bind(ax, *args, **kwargs)\r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/cbook/deprecation.py in wrapper(*inner_args, **inner_kwargs)\r\n    409                          else deprecation_addendum,\r\n    410                 **kwargs)\r\n--\u003e 411         return func(*inner_args, **inner_kwargs)\r\n    412 \r\n    413     return wrapper\r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/axes/_axes.py in scatter(self, x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, verts, edgecolors, plotnonfinite, **kwargs)\r\n   4486         offsets = np.ma.column_stack([x, y])\r\n   4487 \r\n-\u003e 4488         collection = mcoll.PathCollection(\r\n   4489                 (path,), scales,\r\n   4490                 facecolors=colors,\r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/collections.py in __init__(self, paths, sizes, **kwargs)\r\n    951         \"\"\"\r\n    952 \r\n--\u003e 953         super().__init__(**kwargs)\r\n    954         self.set_paths(paths)\r\n    955         self.set_sizes(sizes)\r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/cbook/deprecation.py in wrapper(*inner_args, **inner_kwargs)\r\n    409                          else deprecation_addendum,\r\n    410                 **kwargs)\r\n--\u003e 411         return func(*inner_args, **inner_kwargs)\r\n    412 \r\n    413     return wrapper\r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/collections.py in __init__(self, edgecolors, facecolors, linewidths, linestyles, capstyle, joinstyle, antialiaseds, offsets, transOffset, norm, cmap, pickradius, hatch, urls, offset_position, zorder, **kwargs)\r\n    173         self._hatch_color = mcolors.to_rgba(mpl.rcParams['hatch.color'])\r\n    174         self.set_facecolor(facecolors)\r\n--\u003e 175         self.set_edgecolor(edgecolors)\r\n    176         self.set_linewidth(linewidths)\r\n    177         self.set_linestyle(linestyles)\r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/collections.py in set_edgecolor(self, c)\r\n    828         \"\"\"\r\n    829         self._original_edgecolor = c\r\n--\u003e 830         self._set_edgecolor(c)\r\n    831 \r\n    832     def set_alpha(self, alpha):\r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/collections.py in _set_edgecolor(self, c)\r\n    812         except AttributeError:\r\n    813             pass\r\n--\u003e 814         self._edgecolors = mcolors.to_rgba_array(c, self._alpha)\r\n    815         if set_hatch_color and len(self._edgecolors):\r\n    816             self._hatch_color = tuple(self._edgecolors[0])\r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/colors.py in to_rgba_array(c, alpha)\r\n    339         return np.zeros((0, 4), float)\r\n    340     else:\r\n--\u003e 341         return np.array([to_rgba(cc, alpha) for cc in c])\r\n    342 \r\n    343 \r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/colors.py in \u003clistcomp\u003e(.0)\r\n    339         return np.zeros((0, 4), float)\r\n    340     else:\r\n--\u003e 341         return np.array([to_rgba(cc, alpha) for cc in c])\r\n    342 \r\n    343 \r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/colors.py in to_rgba(c, alpha)\r\n    187         rgba = None\r\n    188     if rgba is None:  # Suppress exception chaining of cache lookup failure.\r\n--\u003e 189         rgba = _to_rgba_no_colorcycle(c, alpha)\r\n    190         try:\r\n    191             _colors_full_map.cache[c, alpha] = rgba\r\n\r\n/usr/local/lib/python3.9/site-packages/matplotlib/colors.py in _to_rgba_no_colorcycle(c, alpha)\r\n    261     # tuple color.\r\n    262     if not np.iterable(c):\r\n--\u003e 263         raise ValueError(f\"Invalid RGBA argument: {orig_c!r}\")\r\n    264     if len(c) not in [3, 4]:\r\n    265         raise ValueError(\"RGBA sequence should have length 3 or 4\")\r\n\r\nValueError: Invalid RGBA argument: 1\r\n```\r\n\r\n**First analys**\r\nIt is only affects the `edgecolor` option, `facecolor` works fine:\r\n```python\r\n# This work fine\r\nplt.scatter([1, 2, 3], [ 0, np.nan, 2])\r\nplt.scatter([1, 2, 3], [ 0, np.nan, 2], facecolor=(1, 0, 0))\r\n```\r\n\r\nIt also seem to be only happening when there are 3 values to plot, 1 or 2 of them being NaNs:\r\n\r\n```python\r\n# These all work\r\nplt.scatter([1, 2], [1, np.nan ],color=(1, 0, 0))\r\nplt.scatter([1, 2, 3, 4], [1, 2, np.nan, 4 ],color=(1, 0, 0))\r\nplt.scatter([1, 2, 3, 4, 5], [1, 2, np.nan, 4, 5 ],color=(1, 0, 0))\r\nplt.scatter([1, 2, 3], [np.nan , np.nan , np.nan ],color=(1, 0, 0))\r\nplt.scatter(np.arange(1000), np.append(np.random.rand(999),np.NaN),color=(1, 0, 0))\r\n\r\n# But those not\r\nplt.scatter([1, 2, 3], [1, np.nan, np.nan ],color=(1, 0, 0))\r\nplt.scatter([1, 2, 3], [ np.nan, 2, np.nan ],color=(1, 0, 0))\r\n```\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\nError was discovered through seaborn, mwaskom/seaborn#2373\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: Mac OS 10.15 / Windows 10\r\n  * Matplotlib version: \u003e= 3.3.0\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): module://ipykernel.pylab.backend_inline\r\n  * Python version: 3.8, 3.9.0\r\n  * Jupyter version (if applicable): 2.2.9\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\r\n","author":{"url":"https://github.com/donok1","@type":"Person","name":"donok1"},"datePublished":"2020-12-04T21:42:04.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/19066/matplotlib/issues/19066"}