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Fix bug in SVD related to values near zero #1314

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merged 4 commits into from
Nov 12, 2023

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rasmusgo
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@rasmusgo rasmusgo commented Nov 9, 2023

This resolves issue #1313.

The problem was in the bidiagonalization where U and V is computed. There is a corner case where U D V doesn't agree how the sign should be handled when the reflection axis has zero magnitude.

This solution fixes the correctness but I would like some input on how to make the test for zero magnitude more efficient.

@Ralith
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Ralith commented Nov 9, 2023

This indeed fixes my issue 🎉

@sebcrozet
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Thank you for this PR!
I pushed a small change: using norm_squared that is marginally more efficient than magnitude because it skips a sqrt.

@sebcrozet sebcrozet merged commit 2e99320 into dimforge:dev Nov 12, 2023
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3 participants