[hjmjohnson]

Make GetInverse of itk::Matrix and itk::VariableSizeMatrix compile for std::complex through a complex-aware itk::bridge::Math::PseudoInverse. Fixes #7058; see also #7061.

Root cause and change

Both GetInverse methods called itk::bridge::Math::SVD, which is real-only (it applies < to the element type). fc7ab6bb550 and a2c58cc9bc4 introduced that path on main only, in no release tag. SWIG instantiates every member, so wrapping IsotropicWavelets failed on three wrapper files.

PseudoInverse dispatches with if constexpr: real types keep the existing SVD path, complex types use an Eigen BDCSVD (thin) with the same rcond rule, explicitly instantiated for float and double in libITKCommon like the real engines. No public signature changes.

Verification

• New GTests: five in itkBridgeMathSVDGTest.cxx (known matrix, Penrose conditions, 20x20 full rank on the BDCSVD path, 20x20 rank-1 with the analytic result, real parity), plus Matrix.GetInverseOfComplexMatrix and VariableSizeMatrix.GetInverseOfComplexMatrix. Expected values are analytic (inverse of [[1,i],[0,1]] is [[1,-i],[0,1]]).
• ITKCommon GTests: 56 of 57 matrix, SVD, and bridge tests pass; the one not run is a legacy-driver test whose driver was not built.
• The three formerly failing IsotropicWavelets wrapper objects compile with 0 errors.
• A standalone complex GetInverse program fails against the old headers and builds against the new ones.
• pre-commit run --all-files passes.

AI assistance

• Tool: Claude Code
• Role: root-cause analysis, implementation, tests
• All changes were reviewed and tested locally before committing.

[greptile-apps]

Confidence Score: 5/5

[Medium impact] The PR appears safe to merge; both previous findings are addressed.

Summary

Adds complex support to Matrix::GetInverse() and VariableSizeMatrix::GetInverse() while keeping the existing real-valued path.

• Fixed-size and runtime-sized matrices can now invert complex values.

_{Reviews (2) · Last reviewed commit: "BUG: Support std::complex in Matrix and ..." · Reviewed by Greptile}

[hjmjohnson]

@greptileai review