[bigfooted]

Proposed Changes

Give a brief overview of your contribution here in a few sentences.

SU2_MON, a python based monitor to view residuals, in case you do not want to view the real time residuals in paraview.
[and my most recent pre-commit is also fixing a bunch of empty lines in unrelated python files]

related to #2879

PR Checklist

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• I am submitting my contribution to the develop branch.
• My contribution generates no new compiler warnings (try with --warnlevel=3 when using meson).
• My contribution is commented and consistent with SU2 style (https://su2code.github.io/docs_v7/Style-Guide/).
• I used the pre-commit hook to prevent dirty commits and used pre-commit run --all to format old commits.
• I have added a test case that demonstrates my contribution, if necessary.
• I have updated appropriate documentation (Tutorials, Docs Page, config_template.cpp), if necessary.

[bigfooted]

[Syphonicc]

Nice addition! This complements the terminal tool from #2879 (su2live) well: SU2_MON covers the windowed case, and su2live covers headless runs over SSH, where there’s no display and often no PyQt5/matplotlib. It also classifies the run (converging with an ETA, stalled, limit-cycling, diverging).

Once this is in, would you be open to a follow-up PR adding a terminal counterpart in bin/? I could do it as a single stdlib-only script next to monitor.py, or as a --terminal mode of SU2_MON, whichever you prefer.

[rois1995]

Please address the three inline findings before merging.

The monitor also needs installation entries: neither SU2_MON nor monitor.py is included in the Meson install paths, so the normal prefix/bin installation does not contain the new command. Please install both with the launcher’s executable permission and relative module path preserved.

Please add small manufactured-history tests covering the header formats, sparse iteration values, reset/cache behavior, incremental append, and incomplete lines, plus a short dependency and launch note.

Validation: the exact reader and plotting methods were exercised with a real Matplotlib Agg canvas. Ten checks passed; four failing behavior assertions reproduced the three inline issues. Installation was checked statically.

[bigfooted]

Meson: monitor.py and SU2_MON are installed to bindir from SU2_PY/meson.build, and the launcher keeps its executable bit and relative path.
Tests: header formats, incomplete header and lines, sparse iterations, incremental append, reset with and without complete rows, and Time_Iter. They stub PyQt5, so they run without a display.
Dependencies: the header comment of monitor.py lists PyQt5, matplotlib, numpy and pandas and says how to launch.