BUG: np.unique_inverse output has wrong shape #25552
Description
Describe the issue:
According to the unique_inverse specification, the inverse_indices output of np.unique_inverse should have the same shape as the input:
second element must have the field name
inverse_indicesand must be an array containing the indices of values that reconstructx. The array must have the same shape asxand have the default array index data type.
In NumPy's current implementation, inverse_indices is a flattened array.
A similar issue exists for numpy.unique_all.
Reproduce the code example:
import numpy as np
x = np.ones((2, 3))
out = np.unique_inverse(x)
assert out.inverse_indices.shape == x.shape, f"{out.inverse_indices.shape=} {x.shape=}"Error message:
AssertionError: out.inverse_indices.shape=(6,) x.shape=(2, 3)Python and NumPy Versions:
>>> import sys, numpy; print(numpy.__version__); print(sys.version)
2.0.0.dev0+git20240106.42fef42
3.9.6 (default, May 7 2023, 23:32:44)
[Clang 14.0.3 (clang-1403.0.22.14.1)]
Runtime Environment:
>>> import numpy; print(numpy.show_runtime())
[{'numpy_version': '2.0.0.dev0+git20240106.42fef42',
'python': '3.9.6 (default, May 7 2023, 23:32:44) \n'
'[Clang 14.0.3 (clang-1403.0.22.14.1)]',
'uname': uname_result(system='Darwin', node='jmdg-macbookpro.roam.internal', release='23.2.0', version='Darwin Kernel Version 23.2.0: Wed Nov 15 21:53:18 PST 2023; root:xnu-10002.61.3~2/RELEASE_ARM64_T6000', machine='arm64')},
{'simd_extensions': {'baseline': ['NEON', 'NEON_FP16', 'NEON_VFPV4', 'ASIMD'],
'found': ['ASIMDHP'],
'not_found': ['ASIMDFHM']}}]