[cmccomb]

Purpose

Run the full-duration Nonlinear_Hydro/ode45/RegularCIC source case at a 0.000625 s physical step with 0.005 s output sampling, using the same pinned script and clock assertions as the successful Regular diagnostic #661. This diagnostic PR is stacked on #661 to preserve its exact-head Regular artifact while running CIC independently. The original published 0.05 s gate and status remain unchanged. The 0.00125 s output-grid A/B does not itself prove 0.000625 s logging neutrality.

Measured diagnostic

Exact-head R2025b workflow 40107064277 completed with a 30,001-row finite history and checked settings [dt, dtOut, nonlinearDt, cicDt, MaxStep] = [0.000625, 0.005, 0.000625, 0.000625, 0.000625] s. Corrected-axis PTO force and absorbed-power samples obey the configured 1.2 MN·s/m damping law to roundoff. Its wave and common-grid times equal the three independently generated first arms in workflow 40107175117. All 38 BEM HDF5 datasets agree in value and STL hashes match.

Across the four arms, source signed PTO work was 20,186,950.852 → 20,127,221.682 → 20,097,460.025 → 20,082,612.183 J. Relative changes contracted 0.296758% → 0.148087% → 0.073934%, satisfying the declared final <0.1% and contraction <0.7 gates. Common-grid work independently passes the same limits. Final common-grid heave/speed/PTO-force/PTO-power changes are 0.000241166 m, 0.000362903 m/s, 435.484 N, and 360.546 W, under the predeclared source limits; all source changes contract. Cached independent Python full-duration motion and PTO direct errors are 0.000241018 m, 0.000362768 m/s, 435.321 N, and 359.533 W, and signed-work difference is 0.073878%, under the unchanged direct limits. The consolidated #655 portable and exact-head gates will independently recheck these measurements before any derived reference is adopted.

This mixed-output source remains a derived step-screened input. The published 0.05 s diagnostic and its qualified_motion status remain visible and unchanged.

[cmccomb]

The successful finest RegularCIC source artifact and its checked configuration were consolidated and independently reproduced by the exact-head convergence workflow in merged #655. This diagnostic PR is superseded.