pymc-devs / pymc-devs/pytensor
ENH: Add slogdet rewrite for block diagonal matrices
Nobody has claimed this yet.
- Dominant language
- Python
- Stars
- 644
- Forks
- 208
- Avg merge
- 2d 14h
- Merged PRs (30d)
- 16
Description
Description
rewrite_det_blockdiag exists for det but there is no equivalent for slogdet.
since det(block_diag(A, B, ..)) = prod(det(A), det(B), ...), slogdet can
also be computed from the individual sub matrices instead of decomposing
the full block diagonal matrix.
Similar to how rewrite_det_blockdiag is implemented in
https://github.com/pymc-devs/pytensor/blob/main/pytensor/tensor/rewriting/linalg.py#L864
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start in pytensor/tensor/rewriting/linalg.py at rewrite_det_blockdiag and compare its handling of block diagonal matrices with the slogdet operation. Add the corresponding slogdet rewrite so the result is computed from the individual submatrices rather than decomposing the full block diagonal matrix. Done means slogdet has equivalent block-diagonal optimization coverage.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- backend, performance
- Issue type
- Feature
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Clearly specified
- Newbie friendliness
- 55/100