Deactivate redundant residual computation before check_convergence.

[jwboth]

Proposed changes

Prior to checking the convergence in check_convergence, the residual is always computed to ask for the recent residual. However, if the tolerance is np.inf, it will actually not be required. The PR only updates the residual if the tolerance is not np.inf.

Types of changes

What types of changes does this PR introduce to PorePy? Put an x in the boxes that apply.

• [ ] Minor change (e.g., dependency bumps, broken links).
• [ ] Bugfix (non-breaking change which fixes an issue).
• [ ] New feature (non-breaking change which adds functionality).
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected).
• [ ] Testing (contribution related to testing of existing or new functionality).
• [ ] Documentation (contribution related to adding, improving, or fixing documentation).
• [X] Maintenance (e.g., improve logic and performance, remove obsolete code).
• [ ] Other:

Checklist

Put an x in the boxes that apply or explain briefly why the box is not relevant.

• [X] The documentation is up-to-date.
• [ ] Static typing is included in the update.
• [X] This PR does not duplicate existing functionality.
• [ ] The update is covered by the test suite (including tests added in the PR).
• [ ] If new skipped tests have been introduced in this PR, pytest was run with the --run-skipped flag.

No updates to tests are added, as the change only works on improving the logic.

[jwboth]

The following thought occurred to me when looking at the change: Does the residual update call perhaps belong inside check_convergence?

I had the identical intuitive reaction when making the changes. If we both agree on that conceptual thought, I can suggest a change for discussion.