René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: Markers can be integers, but numpy integers fail","articleBody":"### Bug summary\n\nThere are workflows where a sequence of markers could end up in a numpy array or a pandas series. If that sequence contains only integers, the marker values will become of type `np.int64`. It is therefore reasonable to expect that these values, different in type but equal to those in the input sequence, not lead to an error.\n\n### Code for reproduction\n\n```Python\nimport matplotlib.pyplot as plt\nfrom matplotlib.markers import MarkerStyle\n\ncaretleft1 = [4][0]\ncaretleft2 = np.array([4])[0]\n\nassert caretleft1 in MarkerStyle.markers\nassert caretleft2 in MarkerStyle.markers\n\n# plt.plot([1, 2, 3], marker=caretleft1) # works\nplt.plot([1, 2, 3], marker=caretleft2) # fails\n```\n\n### Actual outcome\n\n```pytb\n---------------------------------------------------------------------------\nValueError                                Traceback (most recent call last)\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/markers.py:326, in MarkerStyle._set_marker(self, marker)\n    325 try:\n--\u003e 326     Path(marker)\n    327     self._marker_function = self._set_vertices\n\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/path.py:130, in Path.__init__(self, vertices, codes, _interpolation_steps, closed, readonly)\n    129 vertices = _to_unmasked_float_array(vertices)\n--\u003e 130 _api.check_shape((None, 2), vertices=vertices)\n    132 if codes is not None and len(vertices):\n\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/_api/__init__.py:162, in check_shape(shape, **kwargs)\n    160     text_shape += \",\"\n--\u003e 162 raise ValueError(\n    163     f\"{k!r} must be {len(shape)}D with shape ({text_shape}), \"\n    164     f\"but your input has shape {v.shape}\"\n    165 )\n\nValueError: 'vertices' must be 2D with shape (N, 2), but your input has shape ()\n\nThe above exception was the direct cause of the following exception:\n\nValueError                                Traceback (most recent call last)\nCell In[5], line 1\n----\u003e 1 plt.plot([1, 2, 3], marker=caretleft2)\n\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/pyplot.py:3838, in plot(scalex, scaley, data, *args, **kwargs)\n   3830 @_copy_docstring_and_deprecators(Axes.plot)\n   3831 def plot(\n   3832     *args: float | ArrayLike | str,\n   (...)   3836     **kwargs,\n   3837 ) -\u003e list[Line2D]:\n-\u003e 3838     return gca().plot(\n   3839         *args,\n   3840         scalex=scalex,\n   3841         scaley=scaley,\n   3842         **({\"data\": data} if data is not None else {}),\n   3843         **kwargs,\n   3844     )\n\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/axes/_axes.py:1777, in Axes.plot(self, scalex, scaley, data, *args, **kwargs)\n   1534 \"\"\"\n   1535 Plot y versus x as lines and/or markers.\n   1536 \n   (...)   1774 (``'green'``) or hex strings (``'#008000'``).\n   1775 \"\"\"\n   1776 kwargs = cbook.normalize_kwargs(kwargs, mlines.Line2D)\n-\u003e 1777 lines = [*self._get_lines(self, *args, data=data, **kwargs)]\n   1778 for line in lines:\n   1779     self.add_line(line)\n\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/axes/_base.py:297, in _process_plot_var_args.__call__(self, axes, data, return_kwargs, *args, **kwargs)\n    295     this += args[0],\n    296     args = args[1:]\n--\u003e 297 yield from self._plot_args(\n    298     axes, this, kwargs, ambiguous_fmt_datakey=ambiguous_fmt_datakey,\n    299     return_kwargs=return_kwargs\n    300 )\n\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/axes/_base.py:546, in _process_plot_var_args._plot_args(self, axes, tup, kwargs, return_kwargs, ambiguous_fmt_datakey)\n    544     return list(result)\n    545 else:\n--\u003e 546     return [l[0] for l in result]\n\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/axes/_base.py:539, in \u003cgenexpr\u003e(.0)\n    534 else:\n    535     raise ValueError(\n    536         f\"label must be scalar or have the same length as the input \"\n    537         f\"data, but found {len(label)} for {n_datasets} datasets.\")\n--\u003e 539 result = (make_artist(axes, x[:, j % ncx], y[:, j % ncy], kw,\n    540                       {**kwargs, 'label': label})\n    541           for j, label in enumerate(labels))\n    543 if return_kwargs:\n    544     return list(result)\n\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/axes/_base.py:338, in _process_plot_var_args._make_line(self, axes, x, y, kw, kwargs)\n    336 kw = {**kw, **kwargs}  # Don't modify the original kw.\n    337 self._setdefaults(self._getdefaults(kw), kw)\n--\u003e 338 seg = mlines.Line2D(x, y, **kw)\n    339 return seg, kw\n\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/lines.py:394, in Line2D.__init__(self, xdata, ydata, linewidth, linestyle, color, gapcolor, marker, markersize, markeredgewidth, markeredgecolor, markerfacecolor, markerfacecoloralt, fillstyle, antialiased, dash_capstyle, solid_capstyle, dash_joinstyle, solid_joinstyle, pickradius, drawstyle, markevery, **kwargs)\n    392     marker = 'none'  # Default.\n    393 if not isinstance(marker, MarkerStyle):\n--\u003e 394     self._marker = MarkerStyle(marker, fillstyle)\n    395 else:\n    396     self._marker = marker\n\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/markers.py:248, in MarkerStyle.__init__(self, marker, fillstyle, transform, capstyle, joinstyle)\n    246 self._user_joinstyle = JoinStyle(joinstyle) if joinstyle is not None else None\n    247 self._set_fillstyle(fillstyle)\n--\u003e 248 self._set_marker(marker)\n\nFile ~/abc/.venv/lib/python3.13/site-packages/matplotlib/markers.py:329, in MarkerStyle._set_marker(self, marker)\n    327         self._marker_function = self._set_vertices\n    328     except ValueError as err:\n--\u003e 329         raise ValueError(\n    330             f'Unrecognized marker style {marker!r}') from err\n    332 if not isinstance(marker, MarkerStyle):\n    333     self._marker = marker\n\nValueError: Unrecognized marker style np.int64(4)\n```\n\n### Expected outcome\n\n\u003cimg width=\"640\" height=\"480\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/54573c9e-6b6b-4651-a0a6-88213c399cdc\" /\u003e\n\n### Additional information\n\nI will submit a PR.\n\n\n### Operating system\n\n_No response_\n\n### Matplotlib Version\n\n       import matplotlib; print(matplotlib.__version__) 3.10.3\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/has2k1","@type":"Person","name":"has2k1"},"datePublished":"2025-12-11T13:20:04.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":12},"url":"https://github.com/30836/matplotlib/issues/30836"}