Fix column-major parameter ordering in parameterized matmul#72
Merged
dance858 merged 6 commits intoparameter-support-v2from Apr 7, 2026
Merged
Fix column-major parameter ordering in parameterized matmul#72dance858 merged 6 commits intoparameter-support-v2from
dance858 merged 6 commits intoparameter-support-v2from
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CVXPY sends parameter values in Fortran (column-major) order, but the matmul refresh functions assumed row-major/CSR order via raw memcpy. This produced incorrect matrix values for non-symmetric matrices. For sparse matrices, iterate the CSR pattern and index into the column-major source array. For dense matrices, exploit the fact that column-major A is row-major A^T to memcpy directly into AT, then transpose to get A. Also fixes a latent bug where sparse update_values would blindly copy the first nnz values from the full d1*d2 parameter array, which is wrong for matrices with structural zeros. Adds tests for rectangular (3x2) and sparse (3x3 with zeros) cases. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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I cleaned up the code and the tests. We also raise an error now for sparse matrix parameters. |
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CVXPY sends parameter values in Fortran (column-major) order, but the matmul refresh functions assumed row-major/CSR order via raw memcpy. This produced incorrect matrix values for non-symmetric matrices.
For sparse matrices, iterate the CSR pattern and index into the column-major source array. For dense matrices, exploit the fact that column-major A is row-major A^T to memcpy directly into AT, then transpose to get A.
Also fixes a latent bug where sparse update_values would blindly copy the first nnz values from the full d1*d2 parameter array, which is wrong for matrices with structural zeros.
Adds tests for rectangular (3x2) and sparse (3x3 with zeros) cases.