ORNL / ORNL/ReSolve

Support P and Q permutations provided by the user in `LinSolverDirectKLU`

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enhancement
Dominant language
C++
Stars
84
Forks
13
PR merge metrics
No merged PRs in 30d

Description

Summary

Add support for P and Q permutations provided by the user in LinSolverDirectKLU.

Rationale

Ipopt exposes KLU ordering mode 2, which uses P and Q permutations provided by the caller, through resolve_ordering. ReSolve documents this mode, but LinSolverDirectKLU::setup() currently ignores the supplied permutations and analyze() does not use them. As a result, the requested permutations are not applied.

Description

Use the supplied permutations during KLU symbolic analysis and add a test confirming that the ordering is applied.

Additional information

No response

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with LinSolverDirectKLU::setup() and analyze(), then trace how KLU symbolic analysis receives ordering information. Use the existing KLU-related tests as a guide and add coverage confirming that caller-provided P and Q permutations are applied during analysis.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
backend
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
55/100

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