BUG/TST: cluster: incorrect test for seed param of {kmeans, kmeans2} #19683
Description
Describe your issue.
The test added in gh-13972 by @AtsushiSakai incorrectly compares res1 to itself rather than res2 (twice), so does not test the correctness of the seed parameter.
Once the test is corrected to compare res1 and res2, it actually fails due to the elements of the array being in different orders (see the CI of gh-19682).
Reproducing Code Example
def test_kmeans_and_kmeans2_random_seed(self):
seed_list = [1234, np.random.RandomState(1234)]
# check that np.random.Generator can be used (numpy >= 1.17)
if hasattr(np.random, 'default_rng'):
seed_list.append(np.random.default_rng(1234))
for seed in seed_list:
# test for kmeans
res1, _ = kmeans(TESTDATA_2D, 2, seed=seed)
res2, _ = kmeans(TESTDATA_2D, 2, seed=seed)
assert_allclose(res1, res1) # should be same results
# test for kmeans2
for minit in ["random", "points", "++"]:
res1, _ = kmeans2(TESTDATA_2D, 2, minit=minit, seed=seed)
res2, _ = kmeans2(TESTDATA_2D, 2, minit=minit, seed=seed)
assert_allclose(res1, res1) # should be same resultsError message (once corrected)
E AssertionError:
E Not equal to tolerance rtol=1e-07, atol=0
E
E Mismatched elements: 4 / 4 (100%)
E Max absolute difference: 2.5019998
E Max relative difference: 3.09565287
E x: array([[-3.063333, 3.31023 ],
E [-1.947611, 0.80823 ]])
E y: array([[-1.947611, 0.80823 ],
E [-3.063333, 3.31023 ]])SciPy/NumPy/Python version and system information
`scipy` @ `main`