BUG: np.linalg.svd(..., hermitian=True) returns non-unitary vh - #31347
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WarrenWeckesser merged 7 commits intoMay 18, 2026
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BUG: np.linalg.svd(..., hermitian=True) returns non-unitary vh#31347WarrenWeckesser merged 7 commits into
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Explicitly remove 0 from eigenvalue signs to ensure that vh is unitary
sign contains zero here as x @ x = [[1, 0], [0, 0]].
EarlMilktea
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April 28, 2026 05:36
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MEMO: I suspect two CI failures are not related to this PR. |
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seberg
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numpy/linalg/_linalg.py
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Thanks @EarlMilktea. The fix looks correct, but I have some suggested changes in the implementation.
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numpy/linalg/tests/test_linalg.py
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Looks good to me.
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charris
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…31347) * Explicitly remove 0 from eigenvalue signs to ensure that vh is unitary. * Add Hermitian SVD test that has 0 as a singular value.
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BUG: `np.linalg.svd(..., hermitian=True)` returns non-unitary `vh` (#31347)
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PR summary
Currently np.linalg.svd can return non-unitary vh due to sign 0 appearing when input array is singular.
This PR fixes the issue.
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