René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]:  Units behavior of `streamplot`","articleBody":"### Bug summary\n\nAs seen in #27489 `streamplot` does not allow passing unitful data as x/y\n\n### Code for reproduction\n\n```python\nfig, ax = plt.subplots()\r\n\r\nnp.random.seed(19680801)\r\nlimit_value = 30\r\n\r\ndate_array = np.array(\r\n        [datetime.datetime(2023, 12, n) for n in range(1, limit_value)]\r\n    , dtype=np.datetime64)\r\n#date_array_converted = mpl.dates.date2num(date_array)\r\nX, Y = np.meshgrid(date_array, date_array)\r\nU = np.random.rand(limit_value-1, limit_value-1)\r\nV = np.random.rand(limit_value-1, limit_value-1)\r\n\r\nax.streamplot(X, Y, U, V)\n```\n\n\n### Actual outcome\n\n```python\r\nTraceback (most recent call last):\r\n  File \"/home/kyle/play/gh27487.py\", line 22, in \u003cmodule\u003e\r\n    ax.streamplot(X, Y, U, V)\r\n  File \"/home/kyle/src/scipy/matplotlib/lib/matplotlib/__init__.py\", line 1472, in inner\r\n    return func(\r\n           ^^^^^\r\n  File \"/home/kyle/src/scipy/matplotlib/lib/matplotlib/streamplot.py\", line 91, in streamplot\r\n    grid = Grid(x, y)\r\n           ^^^^^^^^^^\r\n  File \"/home/kyle/src/scipy/matplotlib/lib/matplotlib/streamplot.py\", line 330, in __init__\r\n    if not np.allclose(x_row, x):\r\n           ^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/kyle/.pyenv/versions/edge/lib/python3.11/site-packages/numpy/core/numeric.py\", line 2241, in allc\r\nlose\r\n    res = all(isclose(a, b, rtol=rtol, atol=atol, equal_nan=equal_nan))\r\n              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/kyle/.pyenv/versions/edge/lib/python3.11/site-packages/numpy/core/numeric.py\", line 2345, in iscl\r\nose\r\n    dt = multiarray.result_type(y, 1.)\r\n         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\nnumpy.exceptions.DTypePromotionError: The DType \u003cclass 'numpy._FloatAbstractDType'\u003e could not be promoted by \u003cc\r\nlass 'numpy.dtypes.DateTime64DType'\u003e. This means that no common DType exists for the given inputs. For example \r\nthey cannot be stored in a single array unless the dtype is `object`. The full list of DTypes is: (\u003cclass 'nump\r\ny.dtypes.DateTime64DType'\u003e, \u003cclass 'numpy._FloatAbstractDType'\u003e)\r\n```\n\n### Expected outcome\n\nUnits can be passed as at least X/Ya (I could see requiring them to be the _same_ units... or even saying \"this type of plot _shouldn't_ support units\", but would want to be explicit about that.\r\n\r\nI do wonder a bit about `U/V` and whether they should be specified in `delta` units or not? `quiver` can treat them as independent values or as delta values, I believe, but don't see such a distinction on stream lines.\n\n### Additional information\n\nMay be as easy as calling `_process_unit_info` on the inputs, I think.\n\n### Operating system\n\n_No response_\n\n### Matplotlib Version\n\n3.9.0.dev821+gfa6be74127 (~main at time of reporting)\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\ngit checkout","author":{"url":"https://github.com/ksunden","@type":"Person","name":"ksunden"},"datePublished":"2023-12-12T01:12:31.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/27500/matplotlib/issues/27500"}