Open
Description
Bug summary
When using units in matplotlib (in this case pint: https://pint.readthedocs.io/en/stable/) it is not possible to use a single Quantity (magnitude + unit) to specify a single xerr or yerr in ax.errorbar.
Code for reproduction
### WORKING ###
###############
import numpy as np
from matplotlib import pyplot as plt
x = np.array([1, 2, 3])
y = np.array([3, 1.5, 1])
fig, ax = plt.subplots()
ax.errorbar(x, y, yerr=0.5)
plt.show()
### NOT WORKING ###
###################
import numpy as np
import pint
from matplotlib import pyplot as plt
ureg = pint.UnitRegistry()
ureg.setup_matplotlib()
x = np.array([1, 2, 3]) * ureg.meter
y = np.array([3, 1.5, 1]) * ureg.second
fig, ax = plt.subplots()
ax.errorbar(x, y, yerr=ureg.Quantity(0.5, "second"))
plt.show()Actual outcome
/home/user/.local/lib/python3.12/site-packages/matplotlib/axes/_axes.py:3638: UnitStrippedWarning: The unit of the quantity is stripped when downcasting to ndarray.
x = np.asarray(x, dtype=object)
/home/user/.local/lib/python3.12/site-packages/matplotlib/axes/_axes.py:3640: UnitStrippedWarning: The unit of the quantity is stripped when downcasting to ndarray.
y = np.asarray(y, dtype=object)
Expected outcome
No warning / error.
Additional information
No response
Operating system
Fedora 40
Matplotlib Version
3.10.0
Matplotlib Backend
qtagg
Python version
3.12.8
Jupyter version
No response
Installation
pip