Closed
Description
Bug summary
Discovered this in unyt's daily CI jobs: https://github.com/yt-project/unyt/actions
Code for reproduction
import matplotlib.pyplot as plt
import unyt as un
un.matplotlib_support.enable()
fig, ax = plt.subplots()
x = un.unyt_array([1, 2], "cm")
y = un.unyt_array([3, 4], "kg")
yerr = un.unyt_array([0.1, 0.2], "kg")
ax.errorbar(x, y, yerr=(yerr, yerr))Actual outcome
UnitOperationError: The <ufunc 'subtract'> operator for unyt_arrays with units "kg"
(dimensions "(mass)") and "dimensionless" (dimensions "1") is not well defined.
detailed raceback
╭──────────────────────────── Traceback (most recent call last) ────────────────────────────╮
│ │
│ /private/tmp/matplotlib/t.py:10 in <module> │
│ │
│ 7 x = un.unyt_array([1, 2], "cm") │
│ 8 y = un.unyt_array([3, 4], "kg") │
│ 9 yerr = un.unyt_array([0.1, 0.2], "kg") │
│ ❱ 10 ax.errorbar(x, y, yerr=yerr) │
│ 11 │
│ /private/tmp/matplotlib/lib/matplotlib/__init__.py:1348 in inner │
│ │
│ 1345 │ @functools.wraps(func) │
│ 1346 │ def inner(ax, *args, data=None, **kwargs): │
│ 1347 │ │ if data is None: │
│ ❱ 1348 │ │ │ return func(ax, *map(sanitize_sequence, args), **kwargs) │
│ 1349 │ │ │
│ 1350 │ │ bound = new_sig.bind(ax, *args, **kwargs) │
│ 1351 │ │ auto_label = (bound.arguments.get(label_namer) │
│ │
│ /private/tmp/matplotlib/lib/matplotlib/axes/_axes.py:3474 in errorbar │
│ │
│ 3471 │ │ │ │ │ │ xo, yo, marker='|', **eb_cap_style)) │
│ 3472 │ │ │
│ 3473 │ │ if yerr is not None: │
│ ❱ 3474 │ │ │ lower, upper = extract_err('y', yerr, y, lolims, uplims) │
│ 3475 │ │ │ barcols.append(self.vlines( │
│ 3476 │ │ │ │ *apply_mask([x, lower, upper], everymask), **eb_lines_style)) │
│ 3477 │ │ │ # select points without upper/lower limits in y and │
│ │
│ /private/tmp/matplotlib/lib/matplotlib/axes/_axes.py:3434 in extract_err │
│ │
│ 3431 │ │ │ │ │ f"'{name}err' (shape: {np.shape(err)}) must be a scalar " │
│ 3432 │ │ │ │ │ f"or a 1D or (2, n) array-like whose shape matches " │
│ 3433 │ │ │ │ │ f"'{name}' (shape: {np.shape(data)})") from None │
│ ❱ 3434 │ │ │ return data - low * ~lolims, data + high * ~uplims # low, high │
│ 3435 │ │ │
│ 3436 │ │ if xerr is not None: │
│ 3437 │ │ │ left, right = extract_err('x', xerr, x, xlolims, xuplims) │
│ │
│ /Users/robcleme/.pyenv/versions/3.9.7/envs/tmp_unit/lib/python3.9/site-packages/unyt/arra │
│ y.py:1764 in __array_ufunc__ │
│ │
│ 1761 │ │ │ │ │ │ │ │ else: │
│ 1762 │ │ │ │ │ │ │ │ │ raise UnitOperationError(ufunc, u0, u1) │
│ 1763 │ │ │ │ │ │ else: │
│ ❱ 1764 │ │ │ │ │ │ │ raise UnitOperationError(ufunc, u0, u1) │
│ 1765 │ │ │ │ │ conv, offset = u1.get_conversion_factor(u0, inp1.dtype) │
│ 1766 │ │ │ │ │ new_dtype = np.dtype("f" + str(inp1.dtype.itemsize)) │
│ 1767 │ │ │ │ │ conv = new_dtype.type(conv) │
╰───────────────────────────────────────────────────────────────────────────────────────────╯
UnitOperationError: The <ufunc 'subtract'> operator for unyt_arrays with units "kg"
(dimensions "(mass)") and "dimensionless" (dimensions "1") is not well defined.
Expected outcome
This is the output figure with matplotlib 3.4.3
Additional information
The regression bisects to #19526 (8cd22b4)
I note that if replace the last line with
ax.errorbar(x, y, yerr=yerr)
(passing a single array instead of a tuple), it doesn't break on the main branch.
Operating system
Unbuntu
Matplotlib Version
3.5.0
Matplotlib Backend
not relevant (I get an identical error with the 'agg' backend)
Python version
tested on 3.7 to 3.9
Jupyter version
No response
Installation
pip