Record OSWEC variable-yaw step sensitivity on both solvers

PARITY.md

@@ -1141,6 +1141,34 @@ establish Python parity.
 | Other/dynamic: `MOST` | A focused pinned MATLAB reader gate compares Python's decoding of the checked-in 20,750-step TurbSim `.bts` file at selected grid points and with spatial checks at every time. A second source gate executes the published `RunTurbsim.m` on a 1,000-frame excerpt and compares all 249 output times, three velocity components, ten X planes, and 12×12 YZ grid points with Python's lazy advection view; the maximum difference is exactly zero. A third gate compares the six-component force and all three horizontal/vertical fairlead tensions from the pinned direct `nonLinearStaticMooring.m` at ten translated and rotated poses. Observed maximum differences are below `1e-5` N force, `1.5e-4` N m moment, and `5e-6` N tension; the paired gates are `1e-3` N, `1e-2` N m, and `1e-3` N respectively. A [fourth pinned MATLAB gate](https://github.com/cmudrc/wec-sim-python/actions/runs/37957379862) extracts the active BEM rotor function from `MOST_Lib.slx`, generates its IEA 15 MW blade inputs, and compares Python's three-blade root forces and moments at five hub/wind states, including moving and rotated hubs and spatially varying wind. The maximum observed component difference is `1.5e-8` N or N m, below the absolute `1e-4` gate. The published input sets `nonlinearStaticData.flag=1`, leaves `lookupTableFlag=0`, and sets `aeroLoadsType=1` for BEM; its active mooring block is `MooringNLStatic`. The generated mooring and aerodynamic lookup tables are not used by this case. These gates establish wind input, frozen-turbulence time shift, direct static catenary force, and isolated BEM blade loads. The 10 s rotor gate below advances turbine state from prescribed platform motion. A six-coordinate runner couples it to the platform over two pinned 10 s JONSWAP seas (4 m/seed 1 and 6 m/seed 2); the 30 and 60 s developed-sea gates below extend the 6 m condition beyond its wave ramp; a separate 12 m/s constant-wind gate exercises nonzero initial pitch. The published 1,000 s coupled case now has a local independent trajectory comparison and a [passing full-duration source gate](https://github.com/cmudrc/wec-sim-python/actions/runs/38071234135). Other wind/controller regimes remain unpaired. The WaveStar base and fault applications and both WaveBot applications are paired separately above. |
 | Other/dynamic: published-step `Nonlinear_Hydro/ode45` and `OWC/OrificeModel` | Both nonlinear-hydro ode45 cases pass full-duration derived fine-step gates, but the original 0.05 s source trajectories retain force-timing and step-sensitivity gaps. The OrificeModel physical coupled path diverges late, while an explicit source-convention force route passes 130 s body/PTO gates; this does not validate the source air model beyond its Mach threshold. |
 
+#### OSWEC irregular variable-yaw step stability
+
+A [local full-duration audit](docs/evidence/oswec-variable-yaw-refinement.json)
+independently advances the public physical `WEC.run` path at `0.0025` and
+`0.00125` s through the published 600 s irregular sea, using the pinned
+500-component PM realization and 241 selected headings. The published MATLAB
+0.01 s baseline exactly reproduces the archived source body and PTO prefix
+through 250 s. A separate local MATLAB 0.005 s replay reproduces its archived
+160 s half-step yaw within `1.1e-15` rad with identical heading selections;
+the source comparison is not explained by run-to-run input drift.
+
+Against the published MATLAB trajectory, physical Python at `0.0025` s
+passes the unchanged 120 s prefix limits through 160 s: maximum yaw,
+yaw-speed, and PTO-torque differences are `0.000503` rad, `9.93e-5` rad/s,
+and `11.9` N m, with `0.0432%` relative PTO-work difference. The same limits
+fail at 250 s and over the full 600 s, where yaw differs by `0.1154` rad and
+PTO work by `12.55%`. Python's own `0.0025`-to-`0.00125` s step comparison
+passes through 160 s (`0.000243` rad yaw, `0.00599%` work) but fails by 250 s
+(`0.01256` rad yaw) and 600 s (`0.07350` rad yaw, `6.15%` work). MATLAB's
+0.01-to-0.005 s yaw self-change first breaches the `0.0006` rad limit at
+142.93 s; Python versus published MATLAB first breaches it at 166.98 s,
+and Python's own refinement at 167.73 s. Both paths are sensitive to heading
+events over the full duration. These measurements do not establish a
+step-converged 600 s physical reference or change the case badge. The
+separate matched MATLAB 0.005-to-0.0025 s audit addresses the 160 s prefix.
+
+![OSWEC variable-yaw published, source-step, and Python-step yaw differences](docs/figures/oswec-variable-yaw-step-gap.png)
+
 The already gated 300 s OSWEC `Desalination` network and coupled-motion
 comparison now runs from a [portable source fixture](tests/fixtures/matlab/oswec_desalination/README.md)
 and the existing OSWEC BEMIO fixture in ordinary Python CI. The same

docs/evidence/oswec-variable-yaw-refinement.json

@@ -0,0 +1,196 @@
+{
+  "first_yaw_limit_breach_s": {
+    "matlab_0p005_vs_published_0p01": 142.93,
+    "python_0p00125_vs_0p0025": 167.73,
+    "python_0p0025_vs_published_0p01": 166.98
+  },
+  "inputs": {
+    "components": 500,
+    "heading_bank_deg_start_stop_step": [
+      -30,
+      30,
+      0.25
+    ],
+    "peak_period_s": 8,
+    "phase_generator": "matlab",
+    "phase_seed": 1,
+    "python_hydro_sha256": "a423b49b9e09e3303902e576a1f57a696f01c51e877d3271a7d71b59e00493e5",
+    "radiation_memory_s": 40,
+    "ramp_time_s": 100,
+    "significant_wave_height_m": 2.5,
+    "wave_direction_deg": 10
+  },
+  "interpretation": "Both MATLAB source and physical Python paths are step-sensitive after heading-event separation. A separate matched MATLAB 0.005-to-0.0025 s audit examines the 160 s prefix. These results do not establish full 600 s physical parity or increase badge counts.",
+  "matlab_local_half_replay": {
+    "heading_mismatch_samples": 0,
+    "max_pto_torque_Nm": 1.2005330063402653e-10,
+    "max_yaw_rad": 1.0547118733938987e-15,
+    "max_yaw_speed_rad_s": 1.0061396160665481e-16,
+    "wave_max_abs_gap_m": 5.601075159233915e-14
+  },
+  "matlab_published_vs_half_step": {
+    "120": {
+      "heading_mismatch_samples": 87,
+      "pto_torque_Nm": 5.305998087328021,
+      "pto_work_relative_abs_over_published": 0.000151353086660518,
+      "yaw_rad": 0.00018184377993199496,
+      "yaw_speed_rad_s": 4.421665072792003e-05
+    },
+    "140": {
+      "heading_mismatch_samples": 175,
+      "pto_torque_Nm": 9.786727869152003,
+      "pto_work_relative_abs_over_published": 0.0006773907383514274,
+      "yaw_rad": 0.0004593454942990183,
+      "yaw_speed_rad_s": 8.155606557626012e-05
+    },
+    "160": {
+      "heading_mismatch_samples": 1106,
+      "pto_torque_Nm": 95.60088177981993,
+      "pto_work_relative_abs_over_published": 0.005112606866115572,
+      "yaw_rad": 0.005278582322137959,
+      "yaw_speed_rad_s": 0.0007966740148317997
+    },
+    "250": {
+      "heading_mismatch_samples": 8074,
+      "pto_torque_Nm": 316.57413332182364,
+      "pto_work_relative_abs_over_published": 0.02801991505685368,
+      "yaw_rad": 0.015615990273008001,
+      "yaw_speed_rad_s": 0.0026381177776819
+    }
+  },
+  "predeclared_limits": {
+    "pto_torque_Nm": 20.0,
+    "pto_work_relative": 0.001,
+    "yaw_rad": 0.0006,
+    "yaw_speed_rad_s": 0.00015
+  },
+  "python_0p00125_vs_0p0025": {
+    "120": {
+      "coarse_work_J": 1152.872348903958,
+      "fine_work_J": 1152.9816251275417,
+      "gate_pass": true,
+      "heading_mismatch_samples": 30,
+      "pto_torque_Nm": 0.7941711775429212,
+      "pto_work_relative": 9.477707294045721e-05,
+      "yaw_rad": 2.1341708942891613e-05,
+      "yaw_speed_rad_s": 6.618093146188581e-06
+    },
+    "140": {
+      "coarse_work_J": 1467.1989421102437,
+      "fine_work_J": 1467.504883949558,
+      "gate_pass": true,
+      "heading_mismatch_samples": 69,
+      "pto_torque_Nm": 0.9582080342428299,
+      "pto_work_relative": 0.00020847756124048208,
+      "yaw_rad": 4.8575299193998056e-05,
+      "yaw_speed_rad_s": 7.985066952023636e-06
+    },
+    "160": {
+      "coarse_work_J": 1622.1051872547475,
+      "fine_work_J": 1622.0080590687708,
+      "gate_pass": true,
+      "heading_mismatch_samples": 213,
+      "pto_torque_Nm": 5.731104972190224,
+      "pto_work_relative": 5.988144475221336e-05,
+      "yaw_rad": 0.00024298013457740852,
+      "yaw_speed_rad_s": 4.775920810158596e-05
+    },
+    "250": {
+      "coarse_work_J": 1914.1354952389047,
+      "fine_work_J": 1913.0788661318934,
+      "gate_pass": false,
+      "heading_mismatch_samples": 23001,
+      "pto_torque_Nm": 243.30523256027115,
+      "pto_work_relative": 0.0005523186344887763,
+      "yaw_rad": 0.012561744804333058,
+      "yaw_speed_rad_s": 0.002027543604668926
+    },
+    "600": {
+      "coarse_work_J": 2280.1773237134043,
+      "fine_work_J": 2429.556051476256,
+      "gate_pass": false,
+      "heading_mismatch_samples": 132597,
+      "pto_torque_Nm": 1056.1741251073452,
+      "pto_work_relative": 0.06148396027829266,
+      "yaw_rad": 0.07349752964855552,
+      "yaw_speed_rad_s": 0.00880145104256121
+    }
+  },
+  "python_0p0025_vs_published": {
+    "120": {
+      "heading_mismatch_samples": 15,
+      "motion_work_limits_pass": true,
+      "pto_torque_Nm": 1.1100215162839504,
+      "pto_work_relative": 1.8625128437734913e-05,
+      "python_work_J": 1152.872348903958,
+      "source_work_J": 1152.8938216994623,
+      "yaw_rad": 2.575828310640016e-05,
+      "yaw_speed_rad_s": 9.250179302450201e-06
+    },
+    "140": {
+      "heading_mismatch_samples": 49,
+      "motion_work_limits_pass": true,
+      "pto_torque_Nm": 3.37962657289404,
+      "pto_work_relative": 0.00011451851931472298,
+      "python_work_J": 1467.1989421102437,
+      "source_work_J": 1467.3669828044058,
+      "yaw_rad": 0.00014725299195439412,
+      "yaw_speed_rad_s": 2.8163554774222107e-05
+    },
+    "160": {
+      "heading_mismatch_samples": 125,
+      "motion_work_limits_pass": true,
+      "pto_torque_Nm": 11.918596069783916,
+      "pto_work_relative": 0.0004321519557120103,
+      "python_work_J": 1622.1051872547475,
+      "source_work_J": 1621.4044941316083,
+      "yaw_rad": 0.0005031655511895661,
+      "yaw_speed_rad_s": 9.932163391466672e-05
+    },
+    "250": {
+      "heading_mismatch_samples": 6297,
+      "motion_work_limits_pass": false,
+      "pto_torque_Nm": 264.46231635526163,
+      "pto_work_relative": 0.0036411729947648207,
+      "python_work_J": 1914.1354952389047,
+      "source_work_J": 1907.191082573183,
+      "yaw_rad": 0.013789927905163035,
+      "yaw_speed_rad_s": 0.0022038526362938753
+    },
+    "600": {
+      "heading_mismatch_samples": 36276,
+      "motion_work_limits_pass": false,
+      "pto_torque_Nm": 1621.563009950353,
+      "pto_work_relative": 0.125492947446789,
+      "python_work_J": 2280.1773237134043,
+      "source_work_J": 2607.385860475565,
+      "yaw_rad": 0.11542764701165772,
+      "yaw_speed_rad_s": 0.013513025082919704
+    }
+  },
+  "python_environment": {
+    "numpy": "2.5.4",
+    "scipy": "1.18.1",
+    "version": "3.12.7"
+  },
+  "python_runs": {
+    "dt_0p00125_output_sha256": "f3d6ed2e8980ec5bd8ec900747d31444d4308656701edf01223060d1cf6b7416",
+    "dt_0p00125_script_sha256": "81d34286649c290c086b5cb541eccc6a8b66c0a2eb30172e21327df8429d5154",
+    "dt_0p0025_output_sha256": "bca46ccdb9341b456a114e0218108c9fbb53142a100610ea2e207434edf5184a",
+    "dt_0p0025_script_sha256": "886efd0799e56effcc7308d4fc32ee253c0777982c6b8834ac7cbf4b6bb46ab7"
+  },
+  "scope": "OSWEC Variable_Hydro/Passive_Yaw published irregular PM sea, 600 s",
+  "source": {
+    "applications_commit": "d53d4d4c9eda2581f04204f5d394a6ef84bb099e",
+    "archived_step_run": "https://github.com/cmudrc/wec-sim-python/actions/runs/38127365821",
+    "full_duration_files_sha256": {
+      "body": "ca3baf3795b01476410eb92d7c4146d27dbe6d102493f7d001e229c520180777",
+      "components": "053265841734b875d53129e3dd5de92961a43f890a6004f3c68401ae5dcdb384",
+      "heading": "c1ddbc808c05bfe058d3a1eea6d01003034ed1c30a889024eae8aa7bbb0e9c49",
+      "pto": "7e0103e1816f340ffc6aee50efba867a6b297ebf6def8835e9e8652d27812bf4",
+      "wave": "81efb4ca3dd742c3c16793f94c967338cf908e8f860f27bc6783c948e7c237f3"
+    },
+    "published_matlab_run": "https://github.com/cmudrc/wec-sim-python/actions/runs/38035515976",
+    "wec_sim_commit": "0753b2e47f2457c078751dcfe5d251d1767b80ab"
+  }
+}

tests/reference_case_status.csv

@@ -55,7 +55,7 @@ Passive_Yaw/PassiveYawRegression,qualified_motion,Opt-in source ode4 independent
 RM3_PTO_Extension/float,qualified_motion,Published-step opt-in source ode4 pairs; physical Python pairs a derived full-duration FixedStep-only source and exposes published ode4 step sensitivity.
 RM3_PTO_Extension/spar,qualified_motion,Published-step opt-in source ode4 pairs; physical Python pairs a derived full-duration FixedStep-only source and exposes published ode4 step sensitivity.
 Radiation_Force_Options,independent_motion,"All four radiation modes have motion gates; the fitted state-space option is nonpassive."
-Variable_Hydro/Passive_Yaw,mixed_modes,Published regular-wave motion and opt-in source ode4 numerical irregular motion are gated; the physical default differs and the MATLAB source is step-sensitive.
+Variable_Hydro/Passive_Yaw,mixed_modes,Published regular-wave motion and opt-in source ode4 numerical irregular motion are gated; both the MATLAB source and physical Python irregular paths are step-sensitive after heading events through 600 s; no full physical irregular gate is claimed.
 Variable_Hydro/Variable_Mass,independent_motion,Full 900 s body motion and PTO stroke force speed absorbed power and integrated work independently pair across all nine draft states.
 WECCCOMP/WECCCOMP,independent_motion,
 WECCCOMP/WECCCOMP_Fault_Implementation,independent_motion,