377 Commits

Include renames

Author	SHA1	Message	Date
Omar SobhandClaude Fable 5.1	afd1bff6ee	rtx-cfd: overset A-P2 — the patch overlaps the background (OversetPisoSolver), gated S1–S5 ... Background = the embedded solver with a mask from the overlap classification (embedded/{mod,projection}.rs: module split, projection's solve/apply halves, set_overlap, fringe p' Dirichlet by elimination into extra_diag/rhs, anchor dropped, set_inner_stop_factor, phase API begin_step/solve_correction/ apply_correction/end_step; advance rebuilt on the phases — every suite digit- identical, FSI2 default line-for-line). Patch = the curvilinear solver with an acceptor ring (set_side_velocity; set_acceptor_ring/stamp_acceptors/ set_acceptor_correction; acceptor Dirichlet by elimination into PressureSystem.links so the BiCGSTAB stop stays in flux units — identity rows measured unconverged at 2431 iterations; same phase API). overset/overlap.rs: OverlapMap — hole/fringe/active from the patch's own indices (hole = body or k <= nn-1-overlap_rows, DEFAULT_OVERLAP_ROWS = 4 from the 2.9 h depth budget), dual-quad inverse-bilinear donors patch→fringe, lattice donors →acceptors, both invariants asserted, mass-defect measures. overset/mod.rs: OversetPisoSolver — advance (exchange rebuilt BEFORE the predictors from the previous corrected field), alternating Schwarz on the acceptor p' vector with Anderson(3) (plain Schwarz measured 0.82/round: floating patch, Neumann wall) and the previous step's vector as warm start (1 round/corrector at steady state), stop relative to the STEP's p' scale (the MG absolute stop is 1e-9/dt² in pressure — the whole second correction), set_patch_mesh, snapshot/restore carrying the warm-start vector. Gates: overlap linear-exact 1e-13, quadratic orders 1.96/1.99 (acceptors), 1.40/1.91 (fringe); half-couplings: patch with exact acceptors Stokes 2.07/1.98 + 2.08/1.98, upwind 0.84/0.84, background with exact fringe 7.86e-3/2.90e-3/ 1.09e-3 (1.44/1.41); two-mesh MMS n=32/64: background 8.717e-3/4.207e-3 (1.03x/ 0.97x the embedded circle), patch 1.322e-2/6.904e-3 (1.5-1.6x), orders 1.05/ 0.94, patch div <= 5e-13, overlap mass defect 3.6e-3 -> 8.2e-4 of the overlap flux (under the registered 1e-3 from n=64; disclosed at 32); motion: stationary patch through set_patch_mesh bit-identical, snapshot/restore with a pending mesh bit-identical, translating phantom circle 1.22x/1.19x the static level over 4.5 cells. Inherited, disclosed: poisson_equivalence's no-body multigrid pin fails by 3.9e-9 at d46fb0b (M1's commit; verified in a clean worktree). Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-04 19:24:13 -07:00
Omar SobhandClaude Fable 5.1	d46fb0b7a7	rtx-cfd: overset A-P1 GATED — the curvilinear patch moves and deforms under an exact 2-D DGCL ... StepGeometry (motion.rs): time-averaged face vectors S̄_f = ½(S^n + S^{n+1}) and swept volumes δV_f = S̄_f·δc_f — exact for linear node motion on any quad, so Σ sign δV_f = V^{n+1} − V^n is algebra (1.8e-14 measured; the EndOfStep control 2.1e-3). CurvilinearPisoSolver::set_mesh(next) names the end-of-step geometry; advance swaps it in, rebuilds operators + pressure matrix on it (L_f, LSQ gradients, no mesh-velocity term in the projection), keeps the old mesh for V^n and the explicit boundary data; predictor in the conservative ALE form V^{n+1} û = V^n u^n + dt(−Σ sign (F − δV/dt) u_f + ν D + f V^n), written as u·(V^n/V^{n+1}) + … so a stationary mesh is bitwise the static path; fluxes on S̄_f; snapshot carries both meshes; swept_face_rule knob (Trapezoidal default, EndOfStep = negative control). Stokes limit keeps the mesh flux (was dropped with convection) and centres it (upwinding it cost an order: 1.06/1.00). Gates (tests/curvilinear_ale.rs, 11 tests, 83 s): uniform flow on a wiggling AND bending annulus 4.44e-15 over 400 steps, p exactly 0, 0 pressure iterations; control deviates 4.9e-5; stationary mesh through the moving path bit-identical (both diffusion variants); snapshot/restore on the moving mesh bit-identical; Taylor–Green orders unchanged — upwind 0.995/0.976 vs fixed 0.987/0.975 at 1.05× error, Stokes 1.92/1.97 vs 1.94/1.99 at 2.4×, moving annulus 2.11/2.02; linear-field falsifier 1.95/1.92 (annulus), 1.91/1.43 (square, sliding wall nodes). P0 ladders re-run identical to every digit. Rule from the diagnosis: start a moving run ON the t = 0 mesh and sweep less than a cell per step — a first step that jumped 2–4 cells imprinted an O(displacement) error no refinement removed (dt- and motion-independent). Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-04 17:00:04 -07:00
Omar SobhandClaude Fable 5.1	c63d79c300	rtx-cfd/rtx-fsi: overset A-P0 GATED + M1 precision probe — curvilinear collocated PISO: relative-reduction pressure stop (the absolute stop floored |du/dt| at 2e-4 on 64²), line-implicit-n sign fix, adjustPhi; gates: Cartesian reduction 1.37–1.40x the staggered error at orders 0.83/0.90; skewed stretched periodic annulus Stokes orders 2.30/2.06 (explicit and line-implicit), upwind 1.08/0.80; Poiseuille exact to 1e-9 on Cartesian and affine-sheared periodic channels (both diffusion variants), varying-skew channel order 2.02 (v 1.9), cell mass 1e-14; divergence ≤ 1e-11 relative every step; snapshot/restore bit-identical. M1: poisson.rs multigrid hierarchy generic over MgScalar (f32/f64), f64 CG keeps its own fine level; MgPrecision on MultigridParameters/EmbeddedParameters/PisoParameters, set_poisson_precision, harness RTX_FSI2_POISSON_F32 (march + noise probe, printed marker); f64 arm bit-identical in vivo (FSI2 default line-for-line with 08-31), f32 arm holds the noise floor and stall pins and the FSI2 band; poisson_equivalence f32 arm ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-04 12:40:43 -07:00
Omar SobhandClaude Fable 5.1	52da75a3a9	rtx-cfd: curvilinear collocated PISO on a structured patch (overset A-P0, WIP) — PatchMesh (right-handed s,n; periodic seam with shift; face metrics), patch generators (TFI, skewed annulus, sheared/varying-skew channels), CSR + Jacobi-BiCGSTAB, the Zang–Street–Koseff incremental step with the node-based 9-point L_f, LSQ gradients, explicit and line-implicit-n predictors, adjustPhi; tests: mesh metrics (5 green), operators exact on linear fields incl. the seam (green), sparse (2 green), MMS ladder (Cartesian 16/32: 1.37–1.39x the staggered error, order 0.83; n=64 stalls at a |du/dt| floor 2e-4 — open, tolerance-scaling hypothesis), annulus/Poiseuille not yet run ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-04 05:00:08 -07:00
Omar SobhandClaude Fable 5.1	1347bc6772	test(rtx-cfd): fresh-cell falsifier — circle body, far-field probe, kinetic energy per step, speed knob, and the per-flip kinetic-energy split by face class (interior / fresh / dead) ... The split locates the flip's velocity change: 71% (plate) / 61% (circle) on the DEAD faces — fluid faces the wall reaches, overwritten with the wall-side reconstruction in one step (a ~0.25 U_b jump per face) — 27–38% in the interior response, ~1% on fresh faces. Five treatments leave the per-flip impulse/energy unchanged on this falsifier (all measured, none kept unless already committed): substeps, the swept-volume source (40x worse), the fresh-face field extension, face apertures + wall-relative divergence in the projection (-12%, and it breaks the static invariants), and imposing the t^{n+1} wall before the predictor. The impulse is intrinsic to a binary staircase wall that stands still between flips and jumps a cell; the record is in omni-cortex docs/fresh_cell_gcl_campaign.md. Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-03 11:56:04 -07:00
Omar SobhandClaude Fable 5.1	c9492d3e1e	test(rtx-cfd): fresh-cell falsifier extended (circle body, far-field probe, kinetic energy, speed knob) + print-only divergence trace; two candidate fixes REFUTED on it (swept-volume source 40x worse at either sign; fresh-face field extension no effect), both kept default-off with their verdicts ... Phase 1 of omni-cortex docs/fresh_cell_gcl_campaign.md. The mechanism of the moving-body force spikes is measured from four directions: per-flip force amplitude ∝ 1/dt, kinetic energy injected per flipped cell 0.048 J/m independent of dt and body shape (plate row vs circle), felt at a far-field pressure probe, and ∝ U^2 (2.60 / 0.64 / 0.15 J/m at U = 1 / 0.5 / 0.25). A binary mask's wall position jumps by one cell at every flip and the fluid answers with a fixed impulse. Neither the swept-volume source (the wall faces already carry the swept volume — the source double-counts it) nor the fresh-face velocity is where it lives. Next: the virtual cut cell in the projection (apertures + the wall-relative divergence), registered in the campaign doc. Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-03 11:40:28 -07:00
Omar SobhandClaude Fable 5.1	23eb996a9f	test(rtx-cfd): the fresh-cell falsifier — an oscillating flag-sized plate on the FSI2 grid and dt; force spikes track fresh cells (90% at dt) and their per-event amplitude scales as dt^-1.0 (rms dt^-0.44) ... Phase 0 of omni-cortex docs/fresh_cell_gcl_campaign.md (Seo & Mittal's oscillating-body test on this embedded solver). Plate 0.35 x 0.02 m, 1 m/s peak, 80 mm amplitude, still fluid, h = 1/152, dt = 3.24e-4 and its halvings; force sampled as the coupling samples it. Measured: at rest exactly zero; moving, 648 fresh cells per sweep at every dt, rms spike 810 / 1080 / 1490 N/m and MAX spike 6.5e3 / 1.26e4 / 2.56e4 at dt, dt/2, dt/4 — the per-event impulse doubles with each halving (a fixed whole-cell volume error per fresh cell delivered in one step, the raw (dV/dt)|1 - CFL_b| source), against a physical added-mass force of ~1.3e3. RTX_FRESHCELL_LADDER=1 runs the ladder, RTX_FRESHCELL_CSV=<dir> dumps per-step records. Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-03 11:24:24 -07:00
Omar SobhandClaude Fable 5.1	19d8307ae4	test(rtx-fsi): closure schedule by tip speed (CRESCUE_SPEED=<f>), default off ... Route 1 of omni-cortex docs/coupling_rescue_campaign.md §12, registered in docs/closure_scheduling_campaign.md: whenever the last committed tip jump exceeds f x its trailing-2000 peak, open a coarse episode (the s=2 interpolated closure, CRESCUE_COARSE=<M> steps, re-evaluated at each end) BEFORE the step — preventive, because the s=1 closure incubates the crossing instability inside the healthy envelope and no signature-triggered rescue acts early enough (rungs A, C, A' refuted). Speed episodes are expected twice per period: not counted against the runaway-episode cap; the coarse fraction is printed at the end of the march. Verified: FSI2 committed default digit-identical knob-off vs the same-day baseline; fmt + clippy clean. Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-03 09:57:40 -07:00
Omar SobhandClaude Fable 5.1	b66f73aeef	test(rtx-fsi): coupling rescue rung A' — increment trigger (CRESCUE_INC=<K>), default off ... Trigger (c) of omni-cortex docs/coupling_rescue_campaign.md §11: a predictor increment above K x its trailing-2000 median (non-rescued steps; median refreshed every 10 steps) opens a coarse episode (rung C) BEFORE the step's first pass — no pass is spent on a step the episode replaces. Calibrated on the INCTRACE dumps: the anchor u=1.00 r=1 stays under 1.72x for its whole march (K = 2..8 never fire); the (1.27, 2.0) death crosses 3x at 145 steps before its panic and never during resonant growth (the tip-jump trigger fires at 54). Registered K = 3, fallback 4. Needs CRESCUE=1 and CRESCUE_COARSE=<M>. Verified: FSI2 committed default digit-identical knob-off vs the same-day baseline; fmt + clippy clean on the touched files. Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-02 23:01:12 -07:00
Omar SobhandClaude Fable 5.1	7e0f159097	test(rtx-fsi): coupling rescue rung C (CRESCUE_COARSE, burst-local s=2 coarsening) + INCTRACE per-step increment dump — both default off ... Coupling-rescue campaign, continued (omni-cortex docs/coupling_rescue_campaign.md §11). Rung A was refuted 4/4 by mechanism (the substeps reproduce the rejected motion — the runaway is in the converged coupled load at the crossing). Diagnostics on the same death: SUBCYCLE=2 marches GREEN to t=16 (zero bursts), HYST=0.25 dies EARLIER. So: - RTX_{prefix}_CRESCUE_COARSE=<M> (with CRESCUE=1): on a trigger, reject the step and take 2dt coupled steps with the fluid subcycled at 2x (fluid dt unchanged = the s=2 interpolated closure) for M coupled steps, then resume; episodes counted, cap 5 per second of march (loud). rescue.rs: coarse_step / attempt_with generalisation; march loop is now a while loop (a coarse step consumes two indices, the series carries a linear midpoint). VERDICT: refuted 2/2 — the coarse steps themselves cannot close once the state is 10x wild; both rungs act too late (the kinematic trigger is the limitation). - RTX_{prefix}_INCTRACE=<csv>: reporting-only per-step dump (step, t, predictor increment, tol_step, passes, residual, stalled, tip jump) — rung A''s calibration data (healthy anchor vs death). Verified: the FSI2 committed default digit-identical knob-off after each change (same-day baseline); fmt + clippy clean on the touched files. Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-02 22:09:49 -07:00
Omar SobhandClaude Fable 5.1	e76271ac67	test(rtx-fsi): coupling-level rescue rung A (RTX_FSI{2,3}_CRESCUE, default off) + TRACE_FROM autopsy window ... Coupling-rescue campaign (omni-cortex docs/coupling_rescue_campaign.md). Every recorded FSI2 s=1 coupling death is the END of a multi-step runaway (74-march burst scan: green marches never exceed 2.4x their own p95 tip jump; 27/28 deaths burst 5-37 steps first). The traced autopsy of the (1.27, 2.0) death (replay digit-identical, CSV byte-identical) shows a growing period-2 instability of the CONVERGED coupled scheme at the tip's max-velocity crossing: increment x33 and converged load 1e4 -> 1e6 N over 200 steps with the coupling converging on 111 of the first 112 steps. - march.rs: RTX_{prefix}_TRACE_FROM (print-only autopsy window: per-pass residual/load + one line per step with increment, tol_step, retry_at, acceptable, outcome, committed tip jump); RTX_{prefix}_CRESCUE (default off): on a fatal stall or a committed tip jump > 3x the running p95 (trailing 2000 non-rescued steps), reject the step and repeat the interval as 2/4/8/16/32 coupled substeps of dt/n (Mayr-Wall-Gee reduced-step repetition, five repetitions); per-rescue record printed, MarchResult.coupling_rescues/_failures/rescue_records, rate cap 20 rescues per second of march (dies loudly). - rescue.rs (new): the substep ladder — each substep a complete coupled step at dt/n with its own predictor, fresh coupler, C1 velocity chaining, tolerances at the substep's increment; the march's own step path is NOT routed through it (digit identity by construction). - rtx-fea NonlinearDynamicStepper::step_with_dt (step at an explicit dt; step() delegates float-for-float); Fsi2Harness::advance_subcycled_with (explicit fluid dt; advance_subcycled delegates). Verified: FSI2 + FSI3 committed defaults and the noise probe digit-identical knob-off vs same-day / 2026-08-31 baselines; knob ON on the anchor u=1.00 r=1: green, zero rescues, CSV byte-identical to TWIN-1's u1.00.csv; fmt + clippy clean on the touched files. Verdict of rung A on the provocation set: REFUTED 3/3 by mechanism — every rescued interval was carried but reproduced the rejected step's motion (dt/2..dt/32 give the same jump), so the runaway lives in the coupled LOAD at the crossing, not in the time integration; the SUBCYCLE=2 closure marches through the same crossing. The knob stays, default off, as the instrument that measured this. Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-02 21:36:06 -07:00
Omar SobhandClaude Fable 5.1	0f578087ce	feat(rtx-interpret): drift-gated decoder renormalisation (SAEConfig::normalize_gate) ... `normalize_gate: Option<(lo, hi)>` — when set, a decoder column is rescaled to unit norm only if its norm has left the band; columns inside are left exactly as the gradient step made them (divisor 1.0). `None` keeps per-step renormalisation, bit for bit. Why (omni-cortex D629/D630): per-step rescaling was measured doing two opposite things on the same 32-unit SAE. With it off, two runs descended cleanly to floors 3-7x LOWER than with it on — it was fighting descent. Two other runs (lr 0.01, seeds 7 and 99) diverged outright without it — it was also the clamp holding an unstable rate finite, turning a blow-up into a slow oscillation that looked like a healthy dictionary drifting. The band keeps the second role and drops the first; D630 measures whether it does both. The cold-start exemption is applied after the gate, unchanged. Test pins: in-band columns bit-identical before/after, out-of-band pulled to unit, gate None == per-step. Fixture norms sit strictly off the band edge — a hand-scaled 2.0 came out 2.0000002 in f32 and was, correctly, treated as outside. Co-Authored-By: Claude Fable 5.1 <[email protected]>	2026-09-02 20:30:25 -07:00
Omar SobhandClaude Opus 5	9575b84803	style: clear the fmt gate and two lib clippy warnings ... Deferred deliberately while the TWIN-2B/2C campaign had live marches: each march is a fresh `cargo test` invocation, so reformatting `turek_hron_fsi2.rs` mid-campaign would have forced a test-binary rebuild and cost comparability for a cosmetic gate. The family closed, so this is now free. - `cargo fmt --all` across 8 files that had drifted (including the FSI2/FSI3 harnesses touched by the UMEAN/ES override commits). - `rtx-feature-store/tests/integration_tests.rs` had trailing whitespace rustfmt refused to format around ("left behind trailing whitespace" internal error), so the whole file was being skipped; stripped it and the file formats now. - Two `unnecessary_parentheses` warnings in the rtx-transformers lib (`continual/progressive.rs`, `curriculum/mod.rs`) — these were the only rustytorch warnings surfacing through omni-cortex's workspace clippy gate, which is how they were found. No behaviour change. rtx-fsi test binaries still build. Co-Authored-By: Claude Opus 5 (1M context) <[email protected]> Claude-Session: https://claude.ai/code/session_01B1feFAQxjbCRHePUdxuNra	2026-09-02 19:15:53 -07:00
Omar SobhandClaude Fable 5	045e145962	test(rtx-fsi): RTX_FSI{2,3}_ES stiffness override for the TWIN-2 parameter sweep ... The second knob of the TWIN-2 campaign (omni-cortex docs/twin2_stiffness_campaign.md): case_from_env now also reads RTX_{prefix}_ES over the case's benchmark Young's modulus, mirroring UMEAN exactly — digit-identical with the knob unset (verified in vivo on BOTH committed defaults against same-day baselines: FSI2 and FSI3 physics lines diff-clean, only compile/wall timings moved), a loud override line naming the benchmark value and E/E0 when set. The benchmark-inflow physics-band guard in both turek_hron tests widens to a benchmark-CASE guard (u_mean AND e_s bit-identical) so no measured band ever asserts off-benchmark; machinery invariants stay asserted at every inflow and stiffness. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-01 20:50:58 -07:00
Omar SobhandClaude Fable 5	c08abbdc4f	test(rtx-fsi): RTX_FSI{2,3}_UMEAN inflow override for the TWIN-1 parameter sweep ... case_from_env applies the knob over the case's benchmark inflow; unset, the same f64 flows and both committed defaults are verified digit-identical in vivo (physics lines diff-clean vs same-day baselines; only wall-split timing percentages moved). Physics bands in both tests are guarded to benchmark inflow — an off-benchmark march (the sweep) asserts machinery invariants only; its bands live in the TWIN-1 composition harness (omni-cortex docs/twin_composition_campaign.md). The override prints loudly so sweep logs are self-describing. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-31 21:25:30 -07:00
Omar SobhandClaude Fable 5	4aec4e589d	rtx-cfd/rtx-fsi: the FlowField->clawview exporter — real FSI fields through the viewer, end to end ... The march gains RTX_FSI{2,3}_FFLD (MarchConfig::ffld_dir, off by default): every snap_every committed steps (10 when SNAPEVERY is 0), dump the committed FlowField (FlowField::save, bit-exact), the solver's own fluid-cell mask and the interface polygon as text sidecars, plus an index.csv. Reporting-only after acceptance; the FSI2 default with the knob off reproduces every printed digit of the warm-start baseline (uy 3.4921 +- 3.5109, conservation 8.25e-12). The exporter (rtx-cfd examples/ffld_to_vtk): a dump directory -> clawview-readable legacy VTK — per-snapshot 2D triangle meshes (one selectable point scalar --field p|umag|vort, the 0/1 fluid mask as integer CELL_DATA) and an optional space-time volume (--spacetime: frames stacked along z = time, prisms split to tets, POINT_DATA phi), which clawview's slice-plane animation plays as a transient movie. Verified end to end with REAL fields, not synthetic: a 29-frame FSI3 release-transient dump (t 4.0 -> 4.1, 64 MB) exported to 29 snapshots + a 984,312-tet space-time volume; the clawview server loaded both (176,320 nodes volume; 23,877-node snapshots) and served live cross-sections (time slices), vorticity isosurfaces and contours from them. The check caught two real viewer-contract constraints now encoded in the exporter: clawview's legacy-VTK path parses CELL_DATA scalars as INTEGER markers only, and supports exactly ONE point scalar (all POINT_DATA blocks append into `phi`) — multi-field snapshots need the .clwv route, out of scope here. Closes the top open thread of the fifteenth-session handoff (the FSNP/FlowField->viewer exporter); the mesh-repo push and the claw-gds cargo feature remain clawview-side items. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-30 14:45:54 -05:00
Omar SobhandClaude Fable 5	4d2cede7bc	rtx-cfd: warm-start the first corrector's pressure-correction solve — measured 2.5x fewer PCG iterations where it counts ... The MG smoother (neighbour_sum + PCG, 34-40% of the fluid) was the remaining fluid cost. Measured in vivo (FSI2 default, temporary iteration counters): 2.7-3.0 PCG iterations/solve from a zero initial guess. The correction field is temporally correlated step to step, so project() now seeds the FIRST corrector's solve from the previous step's p' (current fluid cells only — the p'=0 invariant on non-fluid cells survives the copy-back); later correctors and the SOR fallback start from zero exactly as before. The corrector restriction is measured, not guessed: the all-correctors draft cut the rigid phase 2.8 -> 1.27 iters/solve but cost 3.9/solve in the coupled phase (baseline 2.56) — corrector 2 solves for a much smaller correction and corrector 1's full-magnitude p' is a WORSE guess than zero there. First-corrector-only: rigid 2.8 -> ~1.1 (best of the three variants), coupled 2.62 ~= baseline. Total PCG iterations on the FSI2 default: 55,088 -> 32,836 (1.68x fewer). Wall: FSI2 default 225 -> 172 s, FSI3 default 343 -> 249 s. Session cumulative (banded LU + indexed SDF + warm start): FSI2 524 -> 172 s (3.0x), FSI3 944 -> 249 s (3.8x). This is a TOLERANCE-LEVEL solver-path change (each projection reaches the same true-residual stop from a different start), and the FSI3 release-window pins fired for the third and fourth time across the drafts — completing the picture: EVERY windowed observable of the [4.0, 4.2] release transient is branch-sensitive (four measured branches now recorded in the test: uy mid 10.77/6.02/2.91/8.88, amp 23.6/25.2/24.6/19.9, ux mid -2.90/-2.91/-2.56/-1.82, retries 2/0/1/1). The release bands are re-pinned as gross-physics tripwires around the measured scatter; the load-bearing regression pins for solver changes are the settled-cycle study bands, whose re-verification under this change is launched (verdicts to solver_status.md). Protocol: FSI2 default green (uy 3.4921 in-band), FSI3 default green under the re-pinned release bands (deterministic across two runs), FSI1 green, noise-probe floors identical, rtx-cfd suite + rtx-fsi quick tests green. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-30 08:54:27 -05:00
Omar SobhandClaude Fable 5	328f65233e	rtx-interpret: decoder cold-start window for reinitialized SAE units ... reinitialize_encoder_neuron_cold / SAETrainer::reinitialize_neuron_cold exempt a freshly reset unit's decoder column from per-step normalize_decoder for cold_steps training steps, so its small random init is not blown up to unit norm before it has learned anything — the mechanism omni-cortex's D605 refutation left as the prime suspect, now testable (D620 downstream). Runtime-only state, not carried through checkpoints (documented); cold_steps 0 is exactly the plain reinit, and existing entry points delegate with 0. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01B1feFAQxjbCRHePUdxuNra	2026-08-30 08:31:08 -05:00
Omar SobhandClaude Fable 5	6c48e53998	rtx-cfd: indexed polygon SDF — bit-identical queries, the fluid's measured hot function cut ... The 2026-08-30 fluid profile (symbolized samples, rigid AND coupled phases of the FSI3 default) attributed the fluid step to the function: polygon_signed_distance 51% rigid / 35% coupled — the embedded mask rebuild and its ghost reconstruction walk every edge of the ~150-vertex interface polygon for every cell-centre and face query, every step. (Also measured, refuting the parked consolidation: Level::new — the MG hierarchy build — is 0.5-0.7% in BOTH phases; caching it would buy nothing. The MG smoother at 34-40% is the honest remaining fluid cost.) PolygonSdf (solvers/incompressible/polygon_sdf.rs): a binned edge index whose query is BIT-IDENTICAL to polygon_signed_distance by construction — per-edge distances use the same float ops, the ring search provably visits a superset of the argmin (convex-projection lower bound sqrt(d_out^2 + ((r-1)b)^2)), and parity XORs the same ray tests over exactly the straddling edges (y-binned). Equality is ASSERTED, not assumed: tests compare to_bits against the brute force over ~40k adversarial points (flag-like walks, random polygons with degenerate zero-length edges, horizontal-edge/vertex-y rays). Wired into EmbeddedBody::polygon and the FSI harness's shared geometry (rebuilt per set_geometry, ~microseconds for 150 edges). Verification — the bar for a bit-exact change is digit identity, and it holds: FSI2 and FSI3 committed defaults reproduce EVERY printed digit of the banded-LU baseline logs (uy 3.7732±3.7920 / 6.0229± 25.2190 mm, conservation 8.26e-12 / 1.49e-12, rigid drags 121.4 / 426.9); rtx-cfd full suite 0 failures; rtx-fsi lib/piston/transfer/ FSI1 green. The study pins need no re-run: the trajectories are unchanged by construction and confirmed by measurement. Wall clock: FSI2 rigid 323 -> 167 s (1.93x), whole default 400 -> 225 s; FSI3 rigid 420 -> 250 s (1.68x), whole default 539 -> 343 s. Cumulative with the banded LU this session: FSI3 default 944 -> 343 s (2.75x), FSI2 524 -> 225 s (2.33x). Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-30 07:47:42 -05:00
Omar SobhandClaude Fable 5	0b4f306ed1	rtx-fea: reduced Newmark (mor::dynamic) + the phase-4a offline replay — the ≥10x gate is REFUTED by measurement at the validated resolution ... The dynamic layer over ReducedNonlinearModel: reduced consistent mass V'MV (full element sum, never ECSW-sampled — ECSW weights are trained on internal-force virtual work and would conserve the wrong inertia), reduced_force_and_jacobian exposed (solve() refactored onto it), and ReducedNewmark mirroring NonlinearDynamicStepper::newmark_newton in reduced coordinates (same predictor, residual, tangent shape; no rescue ladder by design — a reduced Newton death is a finding). TDD (tests/reduced_newmark.rs): identity-basis march reproduces the full stepper to 2.4e-14 over 15 steps (both Newton loops tightened to 1e-10 so only solver rounding separates them); rigid-translation reduced mass = rho*A to 1e-9; a 6-mode POD basis tracks its training trajectory at 4.2e-4 rms against a 1.0e-4 projection floor. Phase 4a (fsi3_ecsw_offline.rs, fsi3_reduced_newmark_replay, env-gated): reduced Newmark replay of the harvested FSI3 trajectory at record cadence (dt_rec = 5x march dt), driven by the recorded end-of-step loads. Measured, m=12/20: - COST (dt-independent, the verdict): 3,068/3,580 us/step at 4.6/5.0 Newton iters — 2.0-2.3x the banded full-order structural step (7,200 us/pass, bandedlu_fsi3_ny62_t85). The >=10x gate needs <=720 us/step; one reduced eval alone costs ~640 us because phase 2 refuted hyperreduction (every eval loops all 70 elements). The gate arithmetic is closed: reduced Newton needs >=2 evals, capping the ROM at ~5x. THE CAMPAIGN GATE (pinned cycle bands at >=10x structural speedup) CANNOT BE MET at the validated resolution. - TRACKING at record cadence diverges in the release transient (dies t=4.35-4.45) — and the RTX_REPLAY_IDENTITY control dies EARLIER (t=4.13) in the exact subspace: the death is the 5x-coarse integration + aliased loads, NOT the reduction. The record-cadence replay cannot judge subspace dynamics; the projection floor (1.1e-3 at m=12) remains the honest subspace statement. Campaign verdict to be recorded in omni-cortex in the pre-registered words. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-30 07:07:49 -05:00
Omar SobhandClaude Fable 5	10c779e96e	rtx-fea: banded LU replaces the dense factorization on the Newton tangent — the march's cost center, fixed ... The 2026-08-29 profile attributed 98% of the structural step (79% of a coupled FSI pass) to LuDirect::factorize — nalgebra's dense full-pivot LU on the 560-DOF tangent, every Newton iteration. The tangent is banded (half-bandwidth ~26: the flag mesh numbers the short direction innermost). BandedLu (solvers/banded.rs): LAPACK dgbtrf-style column-major band storage, partial pivoting with kl fill rows, band limits measured from the CSR pattern per factorize, O(n·kl·(kl+ku)). Swapped into NonlinearDynamicStepper (tangent + rest-state mass solve); LuDirect untouched elsewhere. TDD: 10 manufactured-system tests green first run (recovery to 1e-12 vs exact and vs LuDirect across band shapes incl. full-bandwidth degeneration; zero-diagonal pivoting; indefinite shifted-stiffness tangent; singularity; per-solve refactorization). Solver-path change — full verification protocol run: - rtx-fea 29 binaries 0 failures; rtx-fsi lib/piston/transfer green. - FSI2 committed default: every printed digit IDENTICAL to the 2026-08-28 baseline (uy 3.7732±3.7920 mm, f 2.547, conservation 8.26e-12). FSI1 identical. Noise-probe floors reproduced. - Wall clock: FSI2 coupled phase 233 s -> 77 s (3.0x, 0.60 -> 0.20 s/step); FSI3 coupled 517 s -> 119 s (4.3x). Structure is no longer the cost center; the fluid's MG-caching consolidation is next. Finding 1: newton_rescue's vacuousness guard fired — the 2026-08-24 killer (symmetric 1e4 N mid-swing reversal) converges on the PLAIN path under partial-pivot rounding at every probed combo to 1e5 N. Re-provoked: asymmetric 1e4 -> +1e5 N reversal defeats plain Newton at swing steps 3, 4 AND 5 (not knife-edge); pinned at steps 4, whose coarse-vs-fine gap (0.66x of scale) sits inside the pre-registered 0.75 band — the band is untouched. Finding 2: the FSI3 release pin fired and the PIN was the finding. uy_mid (windowed mean over [4.0,4.2]) moved 44% (10.7684 -> 6.0229 mm) while amplitude (+7%), ux mid (+0.3%) and 5.2x growth all held; the baseline's 2 IQN history-reset retries became 0 — a rounding-level branch flip at unit density ratio (the traced bistable-mask sensitivity). The windowed mean of a growing 5-Hz oscillation is not a rounding-robust observable; its band now covers both measured branches (both recorded in the assertion), amp/ux re-centered at ±35%. New trajectory re-verified deterministic digit-for-digit twice before re-pinning; green in vivo under the new pins. Study-tier pins (FSI3 sticky-mask cycle, FSI2 s=1 benchmark cycle) re-verification launched; results to be recorded in solver_status.md. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-29 23:20:50 -05:00
Omar SobhandClaude Fable 5	8a8da2383d	rtx-fsi: wall-split instrumentation — the STRUCTURE is 79% of the coupled phase ... Per-pass timers (reporting-only, default digits verified identical) around the three pass components. Measured on the FSI3 committed default: fluid 99 s (19.7%), structure 397 s (79.2%), load sampling 0.9%, state save 0.0%. The flag's Newton step costs ~195 ms/pass against ~0.5 ms of element assembly and a ~10 ms-scale 570-DOF solve — either the stepper carries ~20x implementation overhead or the ROM upside is enormous; the ECSW campaign's re-scope decision inverts accordingly (profile the stepper next). Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-29 16:50:28 -05:00
Omar SobhandClaude Fable 5	50e382c046	rtx-fsi: ECSW phase-2 offline study — POD subspace confirmed, hyperreduction refuted at this resolution ... fsi3_ecsw_offline.rs (env-gated on RTX_ECSW_SNAP; committed default is a no-op) measures the three pre-registered quantities on the harvested run-7 flag trajectory, with a numbering self-check (clamped-DOF displacement exactly 0.0 across all 3,294 snapshots). Measured: (1) the flapping manifold compresses 560 free DOFs to 12-20 POD modes at ~0.5% held-out rms projection error — the subspace exists. (2) ECSW has NOTHING TO EXPLOIT on the 70-element flag: the NNLS residual sits at single-element scale until nearly every element joins (31 el -> 10%, 51 -> 10%, 67 -> 2.5%, 70 -> 1e-15; held-out == training everywhere; cycle-only manifold identical) — each macroscopic Quad8 carries non-redundant virtual work, so no sub-percent sample smaller than the mesh exists. (3) full reduced assembly 548 us/eval; ECSW at best 1.4x at a useless 10% residual. ReducedNonlinearModel gains assemble_reduced_force (the measured quantity). The campaign's >=10x structural gate cannot come from hyperreduction at the validated resolution — recorded in the campaign doc with the re-scope options. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-29 15:06:33 -05:00
Omar SobhandClaude Fable 5	d9d8801f1a	rtx-fea: mor gains total-Lagrangian operators and a held-out ECSW residual ... The mor scope was small-strain only ("geometrically linear") — a basis trained on total-Lagrangian trajectories (the FSI flag marches with_total_lagrangian) sampled through small-strain operators would conserve the virtual work of the wrong force. ElementOperator now carries a Formulation (SmallStrain | TotalLagrangian), the TL branch mirroring NonlinearDynamicAnalysis exactly (SVK from Lame parameters, total_lagrangian::internal_force_and_tangent); train_ecsw / ReducedNonlinearModel::new keep their behavior and delegate, with _formulated variants added. ecsw_residual evaluates a trained model's ||Cw - b||/||b|| on arbitrary snapshots — the held-out generalization measurement; on the training set it reproduces training_residual to 1e-12 (pinned). Verified sharply: identity-basis reduced TL solve vs a tight-tolerance full TL solve agrees to 4.4e-15 (machine precision) while small-strain operators land 1.1e-2 away at the same load — the switch is exercised and exact. (At the default 1e-6 convergence criteria the reference itself stops 1.7e-4 short; measured and recorded in the test comment.) Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-29 15:01:09 -05:00
Omar SobhandClaude Fable 5	9fe9d7f74a	rtx-cfd + rtx-fsi: ECSW campaign phase 1 — snapshot dump + FlowField save/load ... FlowField::save/load serialize the complete field state bit-exact (all twelve matrices including *_old, predictors and sources, so a load is a true restart state), with a roundtrip test asserting to_bits equality on every value and rejection of truncated/corrupt files. The march gains an ECSW snapshot knob (RTX_FSI{2,3}_SNAP path, SNAPEVERY, default off): every N committed steps it appends an FSNP record — t, full-DOF displacement/velocity/acceleration (what rtx_fea::mor's pod_basis/train_ecsw consume, plus what the phase-4 dynamic reduction will need) and the committed sparse nodal load for the offline full-vs-reduced replay. Reporting-only: reads committed state after acceptance, no float ops on the solver path. Verified: smoke run's FSNP parsed by an independent reader (570 DOFs, correct record count, physical values); FSI2 committed default digit-identical with the knob off. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-28 21:56:37 -05:00
Omar SobhandClaude Fable 5	366a46b471	rtx-interpret: seeded SAE init + coupled per-unit optimizer reset ... SparseAutoencoder::new_seeded draws encoder/decoder weights via randn_seeded with per-tensor SplitMix64-derived seeds (same derivation as MambaBlock::new_seeded), so identical (config, seed) gives bit-exact SAEs — without it, cross-instance loss comparisons are noise (measured downstream: 0.09 vs 0.65 starts on identical data). SAETrainer::reinitialize_neuron couples the encoder-unit weight reinit with zeroing that unit's optimizer moment rows (encoder row, bias slot, decoder column), so external generate-and-test callers can't reset weights while leaving optimizer state stale — previously only the trainer's internal dead-neuron resampling did both. Note train_step's update rule is plain SGD today, so the moment reset is inert until the Adam path is switched on; the coupling is the contract either way, and a doctored-checkpoint test pins the row/column semantics. Also drops a vacuous assert!(true) smoke test that failed clippy's assertions_on_constants. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01B1feFAQxjbCRHePUdxuNra	2026-08-28 20:49:11 -05:00
Omar SobhandClaude Fable 5	a49602cf16	rtx-fsi: pin FSI3's release response and settled cycle ... Two tiers in the FSI2 pattern. The committed default (t_end 4.2) pins the deterministic release response at the digit-stable measurement (uy 10.7684 +- 23.5726 mm, ux -2.8982; +-35% bands, 2x onset-growth floor against a measured 4.6x). The sticky-mask study configuration (HYST>0, subcycle 2, t_end >= 8.4, ny 62 or 82) pins the settled flapping cycle measured across two grids at t_end 8.5 / window(2.0): uy amp in [38, 72] mm (measured 50.2 / 57.6; the un-flapped release and every pre-hysteresis dead march sit far below, and the reference +-34.9 sits OUTSIDE — landing inside the reference band is a loud finding, not a regression), mids, crossing-frequency in [4.4, 6.8] (covers the estimator's measured beat-scatter — the DFT puts both grids at 5.4-5.6 vs ref 5.46), and drag MEDIAN in [380, 530] (measured 454.0 vs ref 460.2). WindowStats gains drag/lift medians — the honest central loads (the extreme-based mids are noise-dominated at large deformation). Band anchors computed exactly as the test computes them, replayed offline against the run 7/8/10 CSVs (deterministic trajectories). Verified: both committed defaults green with the release pins live, trajectories digit-identical (FSI3's loads line gains the medians, FSI2's output byte-identical). The t_end 8.5 study pin runs at both grids are in flight. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-28 07:56:51 -05:00
Omar SobhandClaude Fable 5	137a62c4ea	rtx-fsi: time-resolved-honest load record — per-step sampling, interval median ... The reported drag/lift were one instantaneous measure_force sample every 10th coupled step, and the embedded-boundary surface force carries zero-mean sign-flipping fresh-cell pressure transients at step scale (measured: +-4,000-scale swings against a +-78 reference while displacements matched the benchmark to 0.1%, and the window MEDIANS sat near-physical). The record now samples the committed field every step and records the interval median — the estimator the CSV analysis supports; ten steps span 2-5% of a flap period, so nothing physical is smeared. Reporting only: measure_force reads the committed state. Verified on both committed defaults against pre-change logs — every displacement, conservation, and coupling digit identical; only the load lines moved, and toward the benchmark: FSI3 drag 628.66 +- 545.11 -> 443.26 +- 148.50 (ref 460.2 +- 27.47, mid now within 3.7%), lift amp 2289 -> 668; FSI2 lift amp 52 -> 28. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-27 14:58:17 -05:00
Omar SobhandClaude Fable 5	bff84ccdcc	rtx-cfd: mask hysteresis — sticky cell classification against a reference mask ... The measured FSI3 killer is the bistable mask: one geometry (|d| identical to 4 digits) samples two load branches (60 vs 120 kN), and the traced s=1 death is the secant walking a 20x load cliff (68,886 -> 1,307,938 N over a 1e-3 candidate change). A sticky band makes the load map single-valued at the crossing: formerly-fluid cells flip only at phi < -band, formerly-solid at phi > band, classified against the mask held at rebuild time — in a coupling loop, the restored committed step-start mask. Band 0 is structurally bit-identical (phi > -0.0 <=> phi > 0.0) and verified digit-for-digit on both committed defaults (FSI2 and FSI3, every physics digit). Measured cost on the translating-circle MMS at band 0.25h: +0.5% field error (u/p ratios 1.17/2.12 vs the no-hysteresis moving levels 1.16/2.11); flip delay = band/(v dt), deterministic. Exposed as RTX_FSI{2,3}_HYST in multiples of h_min. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-26 15:27:09 -05:00
Omar SobhandClaude Fable 5	3207f2d4c6	rtx-fsi: decouple the retry threshold from the widened stall acceptance ... The first STALLX draft used one threshold for both, which silently disabled the history-reset retry for the widened band: a stall in [5x, STALLX x) was accepted unretried where runs 2/3 retried it — caught by trajectory divergence at t = 5.7 (runs 2/3 digit-identical there; the run-5 variant killed at 2.3 h, artifacts preserved as *_unretried_variant_*). Now `retry_at` stays the old 5x-or-increment window (retry semantics bit-identical to the pre-knob code at any STALLX), and `stall_accept` widens only the post-retry acceptance. Default STALLX=5 keeps both thresholds equal — committed defaults unchanged. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-25 07:41:34 -05:00
Omar SobhandClaude Fable 5	992cd76449	rtx-fsi: stall acceptance as a knob (STALLX) — the floor must stay tight; only the rare-event window widens ... FSI3's developed cycle stalls (bistable mask flips at max-velocity crossings) sit at 3.5e-4 against the measured floor 6e-5: run 3 died 16% over the 5x window at t = 7.70. Riding the FLOOR up instead was measured to make it worse — run 4 at floor 1e-4 died EARLIER (t = 6.30) at a HIGHER stall (1.2e-3, 2.4x its window), because the accepted-step scatter IS the wall-velocity noise (tol/dt_c): a looser floor feeds the flip noise it is trying to pass. Keep the floor tight and widen only the counted, bounded stall window: `stall_accept` (RTX_<CASE>_STALLX, default 5 — both committed defaults bit-identical). Precedent: FSI2's s = 1 benchmark run accepted a worst stall of 5.4e-4 the same way and measured 0.1% in amplitude. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-25 05:00:56 -05:00
Omar SobhandClaude Fable 5	647f247601	rtx-fsi: report Newton rescue counts in the coupling-failure panic ... FSI3 run 3 died on a coupling stall 0.2 s after the rescue carried it past run 2's Newton death, and the panic path printed nothing about how many rescues had engaged. Observability only — the panic message now carries rescue_counts. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-25 01:07:49 -05:00
Omar SobhandClaude Fable 5	d2c82af91b	rtx-fea: rescue the nonlinear Newmark Newton — line search, then step subdivision ... Both FSI3 study deaths were the flag's SVK Newton returning ConvergenceFailed{60} inside a coupling pass at a violent mid-cycle load. The plain full-step Newton stays float-op identical (FSI2 and FSI3 committed defaults re-verified digit-for-digit, Newton rescues (0,0)); only on failure does the stepper retry: a backtracking line search on ||R|| (Armijo, alpha down to 2^-29 — 2^-8 was measured too shallow when the tangent K_T + M/(beta dt^2) is near singular and the solved direction enormous and inexact), then 2/4/8/16 Newmark substeps of dt/n, each line-searched. Rescues are counted and surfaced through MarchResult and both FSI test printouts. Measured before writing (tests/newton_rescue.rs): a static tip load from rest NEVER defeats plain Newton (1e6 N converges in 19 its — from a quiescent state the predictor is the current configuration and M/(beta dt^2) regularizes the walk) — pinned as a negative result; the killer is a mid-swing load REVERSAL (1e4 N tip load, 3 steps of swing at dt 5e-3, then reversed: dead in 60 its), the FSI3 turning-point shape — now rescued by the line search alone and consistent with a dt/32 reference march of the same interval (-0.341 vs -0.195 m, same branch), with determinism (bit-identical re-step) and march-continuation pinned alongside. Also: pin the s = 1 FSI2 benchmark cycle at study horizons (iqn / subcycle 1, t_end >= 16: f in [1.85, 2.0], uy amp in [70e-3, 92e-3] — the mode-2 s = 2 cycle fails both bands, so losing the benchmark cycle stays loud). Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-24 19:14:13 -05:00
Omar SobhandClaude Fable 5	555a72cbc0	rtx-fsi: spike-clamp the force-measurement probe ... measure_force integrated raw traction samples while the coupling loads carried the 20x-median clamp — so the s = 1 benchmark run's REPORTED drag/lift were +-4,000-scale garbage against a +-78 reference while its displacements matched the benchmark to 0.1%. Collect, clamp, then integrate, both probes. Reporting only: the committed FSI2 default reproduces its trajectory to every printed digit (uy 3.7732 / 3.7920 mm) and its rigid-phase drag (121.4) with the clamp in. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-24 05:59:18 -05:00
Omar SobhandClaude Fable 5	c1bcdc408e	rtx-fsi: FSI3 floor 6e-5 — the floor rides with the motion; measure it through the cycle ... The first subcycle-2 study (t = 4 -> 8) ran 2.2 s of cycle — over [5, 6] s: +-42.8 mm at 6.2 Hz, trending toward the reference +-34.9 mm at 5.46 Hz from above — then stalled at t = 6.18 s: residual 1.9e-4 against an accept window of 1.5e-4 (5 x the 3e-5 floor the rest-state probe suggested), at a turning point of the cycle where the step increment, and with it the increment-relative part of the window, collapses while the flip noise does not. Floor set from the cycle's measured stall level (window 3e-4). Default re-verified: 581 steps, 3.5 subit/step (max 5), 0 stalls, conservation 1.5e-12, ux -2.90 +- 2.93 mm vs reference -2.86 +- 2.70. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-23 23:41:02 -05:00
Omar SobhandClaude Fable 5	c0666bf22a	rtx-fsi: C3 — FSI3 opened: the added-mass regime, its impulse artefact, and the coupler hygiene it demanded ... The march is extracted from the FSI2 test into a shared tests/fsi2_harness/march.rs (MarchConfig from env / MarchResult / window statistics), the harness parameterised by BenchmarkCase (FSI2, FSI3: inflow, solid density, modulus, rigid-flag drag reference), and turek_hron_fsi3.rs written on top (Re 200, density ratio 1, E 5.6e6). The committed FSI2 default is bit-identical through all of it — every new knob defaults to FSI2's behaviour; re-verified twice to every printed digit (uy 3.7732 / 3.7920 mm). FSI3's first contact, traced pass by pass (RTX_FSI3_TRACE), exposed the added-mass instability in its purest form and, one measured mechanism at a time, what a partitioned coupling at unit density ratio needs: - C^1 interface motion (MarchConfig::c1_interface): a constant per-step interface velocity is a velocity JUMP at each step start, and the incompressible fluid answers with an impulsive added-mass load ~ rho L dv / dt_fluid (8x the physical reaction under subcycling): 1,600 N at release, 48,000 N and a 59 mm response one step later, the flag's Newton dead the pass after. Constant acceleration from the previous end velocity to 2 dd/dt - v_n removes the impulse (loads 1,700-2,400 N). - IQN first-pass relaxation as a knob (initial_relaxation, FSI3 0.05): |1 - omega (1 + g)| must contract; 0.5 diverges past gain 3. - The divergence verdict waits for the secant (IqnIls): the exploratory second pass on a high-gain map legitimately overshoots 10x before the first secant column exists. Pinned by a gain-40 model test. - Kinematic predictor (predictor: "kinematic", velocity only): the structure-alone predictor ignores an added mass comparable to the flag's and overshoots 2-5x, drawing 5-6x loads every first pass; and NOT with the acceleration — Newmark average acceleration carries an inconsistent initial acceleration as a sign-alternating mode (d + dt v + dt^2 a / 2 predicted 22 mm at release; converged 0.14). - Quiescent release (quiescent_release): the structure-alone "consistent" initial acceleration M^-1 F ignores the added mass. - Coupler hygiene (IqnIls): a stalled or diverged step's secant columns are no longer retained (a bistable mask flip's columns extrapolated a 30 mm interface jump on the next step); two-window stagnation detection reports a plateau early instead of bouncing to the budget (a single-window test misjudged a slowly converging step and is recorded as such); trust region tightened to 10x the residual. A noise-column filter at the tolerance was measured to HURT (stalled a converging step at 5.5e-4) and is disabled (threshold 0). - The floor measured, not borrowed (fsi2_interface_noise.rs gains RTX_NOISE_CASE=fsi3): flip jumps 3.6e-4 (12x FSI2's), the subcycle-8 release map stalling near 1e-6, the subcycle-2 map converging to 9e-10; and through the release transient (flag at ~0.3 m/s) the subcycle-8 floor rides up to ~1e-3 with the motion — which moved the FSI3 default to subcycle 2 at a 3e-5 floor. FSI3 committed default (ny 62, release t = 4, t_end 4.2, subcycle 2): 581 steps, 3.8 subit/step (max 8), 0 stalls, 0 retries, conservation 4.3e-13; uy 10.1 +- 27.5 mm and ux -3.1 +- 3.2 mm over the first 0.2 s (reference cycle 1.45 +- 34.90, -2.86 +- 2.70). Machinery invariants pinned; physics bands await the study record. Rigid-flag drag 426.9 vs CFD3's 439.45 (-2.9%). The FSI2 mode-2 study pin (IQN / subcycle 2, t_end >= 16) was measured with the pre-hygiene coupler; re-verify on the next s = 2 study run. 48 lib tests green, clippy clean. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-23 19:43:02 -05:00
Omar SobhandClaude Fable 5	be04e0e233	rtx-fsi: pin the mode-2 flapping cycle under the IQN / subcycle-2 configuration ... Study horizons (t_end >= 16) under RTX_FSI2_COUPLER=iqn RTX_FSI2_SUBCYCLE=2 now assert the measured mode-2 cycle: frequency in [2.05, 2.45] Hz and uy amplitude in [45, 70] mm — bands that admit the settled cycle at either grid (ny=62: 57.6 mm / 2.227 Hz at t=16, 55.9 / 2.224 at t=30; ny=82: 57.1 / 2.236 at t=20) and reject both the wake attractor (3.73 Hz, ±17 mm) and the reference itself (1.93 Hz, ±82 mm) as material changes. The default configuration's pins are unchanged. Module docs brought up to the eleventh-session record. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-23 16:54:12 -05:00
Omar SobhandClaude Fable 5	a342e703a4	rtx-fsi: trust-region cap on the IQN step + increment-scaled stall acceptance ... The s = 1 FSI2 march (deepest rung: 1.955 Hz, ±73 mm mid-growth) found two coupler failure modes at peak motion: - run 1 (budget 12): NotConverged at residual 6.1e-4 = 9% of the step's own increment, after the history-reset retry — killed at t = 11.1 s. - run 2 (budget 30): the deeper budget let an ill-conditioned secant model extrapolate the locally violent map into a candidate interface that swept to the domain wall and crashed the mask build BEFORE any residual guard could fire (t ~ 9.9 s). Fixes, both scale-relative per the absolute-threshold rule: - STEP_CAP = 50: the full quasi-Newton step r + W alpha is capped at 50x the current residual norm, direction kept. Legitimate large Newton steps (near-marginal gains) pass; thousand-fold geometric extrapolations cannot. Pinned by a noisy-map test asserting every iterate's step stays within the cap. - The march accepts a stalled step at residual < max(5 x tolerance, 0.1 x the step's own increment) — the rare violent step near peak motion carries an order-below-increment error, counted like every stall and bounded by the existing stall-fraction assert; the retry trigger mirrors the same bound. 46 lib tests green, clippy clean. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-21 19:14:53 -07:00
Omar SobhandClaude Fable 5	d5f19ea497	rtx-fsi: IqnIls::reset_history — stale secant columns overshoot in rapid transients ... The s = 2 ladder march (resonant growth finally open: 2.3 Hz, amplitude through ±46 mm — 2.7x the wake attractor the loose coupling locked) died at t = 11.12 s with CouplingDiverged at iteration 2: the predictor left a 1e-4 first residual, and the first quasi-Newton update drove it to 1.1e-3. Cross-step secant history assumes the interface Jacobian drifts slowly; columns recorded at much smaller amplitude steered the least-squares direction wrong at 2.7x that amplitude, and the divergence guard read the overshoot as added mass. The map itself converges deeply from a clean start (the noise probe's stall measurement), so the recovery is: reset the history, retry the step once from the predictor. - IqnIls::reset_history(), with a cold-start-equivalence test. - turek_hron_fsi2: on an unaccepted coupling verdict under the IQN coupler, reset + one retry from the predictor (Aitken carries no history — a retry would repeat the identical iteration, so the path is IQN-only); retried steps counted and reported like stalls. Verified end-to-end: the re-run crossed the killing step and marched on (t = 11.18: uy +56 mm, window amp ±50 mm, 1.4 subit/step). 45 lib tests green, clippy clean. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-21 09:34:10 -07:00
Omar SobhandClaude Fable 5	140310b223	rtx-fsi: the noise floor interrogated — smoothing refuted, IQN-ILS lands, tight coupling reopened ... The tenth session ended on "lower the interface noise floor". This builds the levers and measures them, and the measurements overturn the diagnosis: - smooth_tractions: arclength moving average over the wetted surface, area-weighted, smooth normal-similarity factor so corners do not mix and the smoothed load stays continuous in the geometry. Nine unit tests. MEASURED NEGATIVE RESULT: the flip-scan floor is unchanged to 0.2% at radii 1-3h — the flip's load jump is coherent through the fluid field (mask rebuild shifts the pressure around the flipped cell), and a surface average preserves coherent shifts. Default off; the probe pins the attribution so nobody re-reaches for this lever. - IqnIls: interface quasi-Newton with inverse least squares (Degroote 2009) — filtered MGS least squares over secant columns (filter RELATIVE to column norm), cross-step history reuse, per-step set_tolerance. Model-map tests: exact on anisotropic linear maps within dim+2 passes (scalar Aitken provably cannot be), scale invariant, history reuse shortens the next step, stalls at the noise scale instead of diverging (fixture lesson: per-pass noise, not state-dependent noise — the latter has a genuine fixed point). - tests/fsi2_harness/: the FSI2 machinery extracted shared; verified pure code motion (committed release response reproduced to every printed digit). March gains RTX_FSI2_SMOOTH / RTX_FSI2_COUPLER=iqn / RTX_FSI2_REUSE knobs; pinned bands guard the default configuration. - tests/fsi2_interface_noise.rs: the probe. Flip-scan floor at subcycle 8: 3.05e-5 (pinned); smoothing attribution pinned; the cross-subcycle scan recorded but unpinned (the fixed geometry increment's wall-velocity trend, increment/dt_c, swamps the flip signal at small dt_c — a dt_c^2 scaling hypothesis died in that operationalization). THE OPERATIONAL FLOOR — the real release step subiterated at tolerance 1e-9 with residuals traced — converges DEEP at both subcycles: s8 aitken 3.4e-9 / iqn 1.6e-9, s2 both ~6.4e-10 in 5-6 passes. The flip jumps are events at specific geometries, not a floor under every step: the tenth session's subcycle-2 blowup was tolerance mis-budgeting (2e-4 held fixed while dt_c shrank), not an impassable floor. Probe bug found and fixed on the way: stale shared geometry leaked a 4.5e-5 phantom first residual into the first stall run; every measurement now resets the geometry on entry. All 924+17 tests green: lib 44 (was 27), piston 2, curved edge 1, FSI1, the committed FSI2 march (release response identical), the probe. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-21 06:42:05 -07:00
quantumandClaude Fable 5	c36cf2f8a7	rtx-backend-metal: fix swap_dims returning a corrupt strided view ... swap_dims copied the buffer but wrote elements back at their ORIGINAL positions (new_idx was computed with the swapped strides), returning a stride-swapped non-contiguous tensor. Every other op in this backend — elementwise kernels, MPS matmul, to_vec — reads raw buffers and ignores strides, so any transpose consumer (notably the autograd matmul backward, grad_a = grad_c @ b^T) silently computed on untransposed data. Found via CPU-vs-Metal gradient parity on the DigiGraph HetGAT: forward matched, gradients were ~2x off. swap_dims now physically permutes into a contiguous result (reading through the input's strides + offset), and reshape asserts contiguity instead of silently reinterpreting a non-contiguous buffer. 3 new parity tests incl. matmul-after-transpose (25 total pass on-device). Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-21 06:11:38 -07:00
quantumandClaude Fable 5	9297976929	rtx-backend-metal: GPU index_select / index_add via one-hot CSR SpMM ... Override the Backend trait's host-round-trip defaults: gather is S @ X with S the [E x N] one-hot selection CSR; scatter-add is the adjoint S^T @ X, whose CSR is built directly by counting sort so duplicate indices land in one row and the spmm kernel (one thread per output element) accumulates them without atomics. CSR matrices are cached per thread keyed by the exact index list + dims, so a static graph topology (GNN message passing) builds each matrix once. Host fallback on degenerate shapes or any sparse-pipeline failure. 13 new parity tests vs CPU reference: duplicates, unreferenced rows, D=1/2/3, 15k x 5k x 64 gather/scatter, cache reuse, adjoint roundtrip. Verified on-device that the SpMM path (not the fallback) serves all 13. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-21 05:56:23 -07:00
quantumandClaude Fable 5	2e23d0f4c6	rtx-backend: gate CUDA parity tests to x86_64 Linux ... The rtx-backend-cuda dev-dependency is already gated to cfg(all(linux, x86_64)) in Cargo.toml, but the test file imported it unconditionally, so cargo test -p rtx-backend failed to compile on macOS. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-21 05:52:03 -07:00
quantumandClaude Fable 5	72b41e3167	rtx-backend-metal: align to current rtx-metal API ... rtx-metal dropped tensor_ops::{sin,cos,pow,clamp,gt_scalar,var} and never had nn::{max_pool2d,avg_pool2d}; nn::conv2d grew a scalar 14-arg signature. Give the missing ops correct host fallbacks (the sum_dim pattern), and dispatch conv2d to the Metal kernel when its restricted signature applies (symmetric stride/padding, dilation 1, groups 1), host fallback otherwise. cargo test -p rtx-backend-metal: 22/22 parity tests pass on-device (M5). Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-21 05:52:03 -07:00
Omar SobhandClaude Fable 5	4e90177aa9	rtx-fsi: C2 — FSI2's coupled march, and the wrong attractor measured ... The unsteady coupling on the piston pattern with the real solvers: per TIME STEP, Aitken subiterations of (8x-subcycled embedded TVD/multigrid fluid <-> flag nonlinear-Newmark step), the fluid re-runnable through snapshot/restore + a field clone, the flag re-runnable because the stepper commits nothing, the moving polygon carrying the flag's actual interface velocity. Conservation 8.3e-12 over 9,263 coupled steps; the rigid phase reproduces this solver's own CFD2 values at both grids before anything couples. What the 30 s studies measured (ny = 62 AND 82, three protocols): the coupled system self-excites into a wake-forced cycle at 3.729/3.728 Hz with uy(A) +-17.3 mm at both grids - grid-converged, protocol- independent, kinematically genuine (ux locks 2x uy) - and NOT the benchmark's mode-2 resonant cycle (1.93 Hz / 81.6 mm; the flag's vacuum mode 2 is 1.9245 Hz). Diagnosis measured stepwise: the staggered phase lag starves the resonant channel (a subcycle=2 probe redirected growth to 1.9 Hz as predicted), and tighter dt_c is blocked because wall- velocity noise = displacement-tolerance / dt_c while the needed tolerance sits below the discrete interface noise floor (~1.3e-4 at full inflow, mask flips through beta dt^2/m). The route to the benchmark cycle is lowering that floor, not iterating against it. Robustness, both measured: rare wild tractions (19 samples in 2.4M) clamped at 20x the sample median - clamped, not dropped: a hard drop makes the pass discontinuous and the subiteration bounces at step scale; and Aitken "divergence" verdicts within 5x tolerance accepted as noise bounces over well-predicted steps (counted, bounded). The committed default (t_end = 7, ~9.5 min) pins the deterministic release response (uy 3.773 +- 3.792 mm, band +-35%); study horizons >= 25 s pin the measured 3.73 Hz attractor so any material change is loud. Full study record in the module docs and omni-cortex solver_status.md. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-21 02:45:43 -07:00
Omar SobhandClaude Fable 5	4534d90684	rtx-fea + rtx-cfd: the single-step seams FSI2 stands on ... rtx-fea: NonlinearDynamicAnalysis refactored onto a NonlinearDynamicStepper - set_nodal_forces on both (the interface load of a coupling subiteration, replaceable between steps and between subiterations of one step); - step(&DynamicState) is a pure function of the start-of-step state and the current forces - commits nothing, so a partitioned coupling re-runs one Newmark step to the interface fixed point (the piston semantics); - run() marches through the same stepper: one code path, pinned from both ends (linear limit, CSM3, and a new manual-drive == run() assertion); - new test: a nodal step load oscillates about the *static* nonlinear analysis's deflection (cross-code-path, mean within 3%, amplitude 6%), with re-run determinism and force-swap sensitivity asserted mid-march (a one-step response to a force change is ~ beta dt^2 - the first assertion draft demanded 10% and was corrected against the physics). rtx-cfd: the subiteration seam and the moving no-slip closure - EmbeddedPisoSolver::snapshot()/restore() (mask + time + init flag; the mask is now Clone): re-running a fluid step within a subiteration is bit-identical to never having diverted - proven on a moving body with cells flipping in the re-run window; - polygon_interface_velocity: nearest-edge linear interpolation of per-vertex velocities, exact for the linear-along-edge boundary data a finite-element interface hands over - the no-slip closure that replaces FSI1's zero-velocity polygon. Suites: rtx-fea 567, rtx-cfd 325, rtx-fsi piston+transfer - all green. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-20 20:00:49 -07:00
Omar SobhandClaude Fable 5	c0f5a86f03	rtx-cfd: the embedded-body pieces FSI1 stands on (belongs with b82f307) ... EmbeddedMask::traction_at (the per-sample traction factored out of surface_force, so a coupling loop can load a structure at its own quadrature points), EmbeddedBody::polygon and the public polygon_signed_distance (a deformable interface as a vertex list, usable behind a lock through EmbeddedBody::from_sdf). Left unstaged by mistake in b82f307 — that commit's FSI1 test needs these to compile. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-20 17:22:44 -07:00
Omar SobhandClaude Fable 5	b82f307cae	rtx-fsi + rtx-cfd + rtx-fea: FSI1 — the coupled cylinder and flag ... The summit rung C1: all the verified pieces joined into the first coupled Turek–Hron computation (rtx-fsi/tests/turek_hron_fsi1.rs). The embedded fluid computes tractions on the DEFORMED flag surface (EmbeddedMask::traction_at, factored from surface_force); the flag's wetted boundary is a polygon whose vertex list sits behind a lock, so the moving-body mask rebuild picks up every shape update (EmbeddedBody::polygon + pub polygon_signed_distance); WettedSurface — rebuilt on the deformed interface every subiteration — carries the loads to the flag's boundary nodes (NonlinearStaticAnalysis::set_nodal_forces); Subiterated::aitken drives the exchange, each pass marching the fluid to flag-load stagnation so the coupling map is a function of geometry, not of the fluid's transient. Result (ny = 62, 6 Aitken passes, 420 s): coupled drag 15.360 (+7.5%, the rigid CFD1 band at this grid), lift 0.7977 (+4.4%), ux(A) 2.647e-5 vs 2.270e-5 (+16.6%; +6.1% at ny = 82), uy(A) 3.90e-4 vs 8.21e-4 at h = 6.6 mm and 1.124e-3 (+37%) at h = 5 mm — the resolutions BRACKET the reference through the flag's 3 -> 4-cell thickness transition, like the rigid-flag lift; conservation 7.4e-12 every pass. Bands asserted are the measured ones; RTX_FSI1_NY runs studies. Two real rtx-fsi defects found by this rung (15th and 16th of the campaign), both regression-tested (tests/transfer_curved_edge.rs): 1. solve_weights built its constraint Gram from RAW coordinates: the condition number grows as (position/spacing)^2 — ~1e4 for a flag edge at x ~ 0.26 with 5 mm spacing — and the 4x4 SVD pseudo-inverse lost enough accuracy that the (correctly strict) partition-of-unity / reproduction verification rejected healthy neighbourhoods: the operator's behaviour depended on WHERE the interface sat. Now centred on the face and scaled by the neighbourhood radius — identical constraints, O(1) conditioning, translation-invariant. 2. A NEARLY collinear neighbourhood (the nearest nodes of a face on a smoothly deformed edge: y is almost linear in x, off by the curvature sagitta) cannot satisfy exact centroid reproduction with bounded weights — the offending singular value is too large to truncate and too small to invert. The recruitment now widens (8 -> 16 -> 32 -> all) until the verified constraints hold; for a thin structure that pulls in the opposite face, exactly the transverse spread the system needs. Findings measured before believed: the transfer is faithful (a strictly local two-node split of the same tractions moved the tip by 2%); the uy error is the sampled lift PROFILE on a 3-cell flag (a uniform distribution of the same net lift bends 4x more), confirmed by the resolution study; TVD limiter chatter (+-0.5% steady load — limited schemes stall short of machine steady state) defeats steady fixed-point coupling, so steady coupled cases run upwind while the time-marched FSI2/FSI3 keep TVD; and the mask never chattered at FSI1's sub-cell amplitude (fluid-cell count constant through every pass). rtx-fsi 29 -> 31 green (lib 27, piston 2, curved-edge 1, FSI1 1). Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-20 17:22:27 -07:00
Omar SobhandClaude Fable 5	38ca5ef080	rtx-fea: S2 — nonlinear Newmark, and Turek–Hron CSM3 to 0.1–1.3% ... analysis::nonlinear_dynamic::NonlinearDynamicAnalysis: Newmark-beta with a full Newton solve on the internal force inside every step — residual F_ext − f_int(u) − M a(u), consistent Jacobian K_T(u) + M/(beta dt^2), the same total-Lagrangian St. Venant–Kirchhoff / small-strain seam the nonlinear static analysis uses, consistent mass assembled once (element mass is configuration-independent in a total-Lagrangian setting), undamped, homogeneous Dirichlet only (prescribed interface motion arrives with the FSI rung). The existing NewmarkStepper stays what it is: the right tool for constant matrices. Verified (tests/nonlinear_newmark_csm3.rs): - linear limit (strains ~1e-9): the TL nonlinear stepper reproduces the verified linear NewmarkStepper on the same dense M, K, F to a max deviation of 1.7e-16 — 1.3e-9 of the oscillation amplitude — over 120 steps; - Turek–Hron CSM3 (35x2 Quad8, dt = 0.005, gravity switched on at rest, 6 s): ux(A) = −14.291 ± 14.291 mm vs the reference −14.305 ± 14.305 (0.1%); uy(A) = −63.644 ± 64.295 mm vs −63.607 ± 65.160 (0.06% mean, 1.3% amplitude); frequency 1.1020 Hz vs 1.0995 (0.23%); two Newton iterations per step throughout; the undamped amplitude persists (half-window drift 0.2%). rtx-fea 564 -> 566 green (full suite). With this the S-side of the Turek–Hron ladder is complete: statics (CSM1/CSM2) and dynamics (CSM3) both land on the benchmark. Next rung is the coupling: FSI1 with the embedded fluid, the TL flag, and rtx-fsi's transfer rebuilt on the deformed interface each subiteration. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-20 14:02:15 -07:00
Omar SobhandClaude Fable 5	0ad31abb6b	rtx-cfd: F2 — the moving embedded body, and falsifier 3 measured ... EmbeddedPisoSolver::set_moving_body: the mask is rebuilt at the end-of-step geometry every step, and the new mask's ghost values are reconstructed FROM THE PREVIOUS CORRECTED FIELD (EmbeddedMask:: impose_from — the boundary-history principle extended to a moving wall), so a stationary body run through the moving path is bit-identical to the static path, which is the first test. A velocity face that flips solid -> fluid enters the new interval holding exactly the ghost reconstruction the previous step left on it — a consistent near-wall value, not garbage; a fresh pressure cell is refilled from its fluid neighbours before the predictor's gradient can read the value it kept while inside the body. The body must move under a cell per step (the convective dt limit already enforces this for bodies slower than the local peak velocity). EmbeddedResult reports fresh_cells. tests/embedded_moving.rs: - a stationary body through the moving path: 0.0 difference over 100 steps (and zero fresh cells, identical ghost corrections); - a circle (r = 0.2) translating through the steady manufactured field with the exact field as its surface velocity — the solution must hold still while the mask sweeps 84 cells fresh over 300 steps at n = 32: max L2 velocity error 9.85e-3 = 1.16x the static steady level (8.489e-3), max L2 pressure error 4.67e-2 = 2.11x the static level (2.22e-2), bulk |div u| 1.6e-7, projection residual 5.9e-9 every step. That pressure ratio is the geometry decision's falsifier 3 (omni-cortex docs/turek_hron_geometry_decision.md): fresh-cell transients sit at ~2x the static discretisation error, not orders above it — the falsifier does not fire and no cut cells are needed. Measurement note, recorded in the test: the divergence of body-adjacent cells read after the end-of-step ghost re-imposition is a one-step lag by design (the next projection honours the re-imposed prescribed fluxes — the same lag the static path has); the continuity claims are the projection residual and the bulk divergence over all-fluid-faced cells. Deferred: an oscillating-cylinder benchmark against published force histories (Duetsch et al. 1998) when the FSI rungs need it. rtx-cfd 321 -> 323 green. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-20 13:07:28 -07:00