Preconditions

• G2.5 human method choice is recorded.
• code/matlab/Qx/qx_code_plan.md exists.
• Required cleaned data and profile exist.
• The plan targets MATLAB or 北太天元.

Legacy artifacts may be read during migration but do not override the human decision.

Workflow

1. Read the code plan, decision ledger, method card, probe conditions, and data profile.
2. Confirm scope: approved main plus usable baseline. Implement a fallback only after activation.
3. Generate conservative .m files under code/matlab/Qx/.
4. Prefer basic matrix/table operations and avoid optional toolboxes unless the plan approves them.
5. Save tables, metrics, useful figures, and run_summary.json under results/Qx/experiments/roundN/.
6. Evaluate output-degeneracy and fallback-trigger metrics required by the plan.
7. Use diary or another full log only for a failure or reproducibility warning.
8. Run in the available compatible runtime. If unavailable, report the unexecuted state explicitly.
9. Hand off to code-reviewer.

Script Layout

code/matlab/Qx/
├── qx_code_plan.md
├── qx_baseline.m
├── qx_main.m
└── run_all.m        % only when useful

Do not create scripts for unapproved candidates or a duplicate README.

Compatibility Rules

• Prefer readtable, readmatrix, writetable, writematrix, save, load, and fullfile.
• Use rng(2026) or the recorded seed.
• Use jsonencode when supported; otherwise write the required JSON fields deterministically.
• Avoid Live Scripts, App Designer, GUI code, Simulink, and toolbox-only functions unless explicitly approved.
• Note any 北太天元 compatibility risk in the run summary.

Run Summary

Follow the model-code-analyzer contract, including approved decision ID, roles, paths, metrics, output-degeneracy evidence, fallback state, timing, seed, environment, warnings, and errors.

Rules

• Do not change the selected mathematical method.
• Do not access or overwrite raw data.
• Do not fabricate successful execution when MATLAB/北太天元 is unavailable.
• Keep only evidence-bearing intermediate outputs.
• Separate Type 1 diagnostics from paper figures.

Verification

• Main and baseline are directly comparable and both executed when a runtime is available.
• Fallback code exists only when activated.
• Formal outputs and run summary exist.
• Compatibility, seed, inputs, warnings, and errors are recorded.
• Required concentration/degeneracy checks are saved.
• Next handoff is code-reviewer.