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BUG: Cannot call np.median on datetime array #26216
Description
Describe the issue:
Not sure if this is by design or actually a bug but one cannot call np.median on datetime arrays.
This was also reported on StackOverflow some years ago.
Reproduce the code example:
import numpy as np
a = np.array([np.datetime64('2005-02-25'), np.datetime64(1, 'Y')])
np.median(a)Error message:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<__array_function__ internals>", line 180, in median
File "/Users/guilhermeleobas/micromamba/envs/numba/lib/python3.9/site-packages/numpy/lib/function_base.py", line 3793, in median
r, k = _ureduce(a, func=_median, axis=axis, out=out,
File "/Users/guilhermeleobas/micromamba/envs/numba/lib/python3.9/site-packages/numpy/lib/function_base.py", line 3702, in _ureduce
r = func(a, **kwargs)
File "/Users/guilhermeleobas/micromamba/envs/numba/lib/python3.9/site-packages/numpy/lib/function_base.py", line 3847, in _median
rout = mean(part[indexer], axis=axis, out=out)
File "<__array_function__ internals>", line 180, in mean
File "/Users/guilhermeleobas/micromamba/envs/numba/lib/python3.9/site-packages/numpy/core/fromnumeric.py", line 3474, in mean
return _methods._mean(a, axis=axis, dtype=dtype,
File "/Users/guilhermeleobas/micromamba/envs/numba/lib/python3.9/site-packages/numpy/core/_methods.py", line 179, in _mean
ret = umr_sum(arr, axis, dtype, out, keepdims, where=where)
numpy.core._exceptions._UFuncBinaryResolutionError: ufunc 'add' cannot use operands with types dtype('<M8[D]') and dtype('<M8[D]')Python and NumPy Versions:
1.22.4
3.9.18 | packaged by conda-forge | (main, Dec 23 2023, 16:35:41)
[Clang 16.0.6 ]
Also tried on Numpy 1.24, 1.25 and 1.26.
Runtime Environment:
No response
Context for the issue:
No response
Activity
mwanink commentedon Apr 6, 2024
I could take a look at this if nobody else has yet!
seberg commentedon Apr 10, 2024
This may need a bit of thought/discussion (i.e. may be a bit slow). Since similar things happen in
meanalso. You cannot implement mean assum()/countor the interpolation here using addition for datetimes.OTOH, if you can rephrase the computation to support it without breaking/slowing down the (fragile) logic for other types, I think that would definitely be OK.
(Although, maybe nobody will mind a small special case for datetimes.)
kasmith11 commentedon Apr 29, 2024
@seberg is this still an open discussion? If so, do you feel as if this would be a good first contribution?