Adds shapecurve.is_feasible() (a non-mutating refactor of solve()'s check
phase) and a shapecurve_prune flag composing the DP's exact feasible/
infeasible verdict with operators.predicted_shape_fails' existing heuristic
prune: DP-feasible vetoes a heuristic prune outright; DP-infeasible only
hard-prunes when the incumbent already has zero total fails (exact, since
infeasible proves the shape-fail floor is >=1); otherwise defers unchanged
to today's heuristic threshold. Conservative by design since a wrong prune
is unrecoverable.
Validated 0/400 false negatives across two structurally distinct plots
(harbor-house-l0 + a newly-added programme-house sweep, the first genuinely
non-rectangular plot this DP has been checked against). The real
driver.search A/B on harbor-house-l0 measured NULL (byte-identical off/on)
for a root-caused, pre-existing reason: predicted_shape_fails rarely
triggers organically at this scale, so neither new branch had an opening to
fire -- not a defect in this change. Full writeup: DESIGN.md §37.5.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LSwQwpEaHFBkeVSDDWd75S
User review caught a real gap: the DP approximated each quad's (w,h)
via its axis-aligned bounding box in global x/y, correct only because
harbor-house-l0's plot happens to be near-parallel to its own axes
(~7.5% area error). A real building's orthogonal walls need not align
to the survey/CRS axes at all -- confirmed by rotating the plot 45deg,
where the old bbox error jumped to 102% (up to 2x for a rotated square).
Fixed in two steps: (1) measure (w,h) from edge lengths
((edge0+edge2)/2, (edge1+edge3)/2, the geometry.aspect() pairing)
instead of global bbox -- rotation-invariant by construction. (2) this
alone regressed accuracy (99.0% -> 95.5%) because a child's own
rotation parity determines whether its local edge0/edge2 pair aligns
with its parent's edge0/edge2 or edge1/edge3 -- not a matter of degree
to measure empirically (as attempted first) but an exact algebraic
identity (verified float-exact: left.w + right.h == parent.w whenever
left.rotation is even and right.rotation is odd). _child_contrib now
applies this directly, replacing the empirical _orientation/
annotate_orientations machinery entirely -- simpler and correct.
Re-validated: 99.0% agreement on harbor-house-l0 unrotated (back to
matching the original result, same 2 residual mismatches, 0 false
negatives), 100% agreement at 97x speedup on the same plot rotated
45deg (new, via validate_shapecurve.py's rotated_plot_dir helper).
DESIGN.md §37.2 updated with the full correction history.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LSwQwpEaHFBkeVSDDWd75S
Prototype + validation for an exact size/width/proportion feasibility DP
over a frozen slicing topology, replacing the ~80-200 eval Nelder-Mead
inner loop's approximate answer to the same question with one bottom-up
pass (experiments/shapecurve_spike.py). Leaf feasible regions are exact
FAIL_THRESHOLD-inversions of fitness.py's quality_size/width/proportion;
internal-node composition runs on a shared discretised grid.
Validated on harbor-house-l0 (experiments/validate_shapecurve.py, 200
random topologies vs NM minimising shape-fail-count directly): 99.0%
agreement (0 false negatives), 93.6x speedup at grid_n=150, plot-level
bbox approximation error quantified at +7.5% (root-causing both observed
false positives). All three acceptance criteria cleared -- see DESIGN.md
§37.2 for full results and the caveats/scope not covered (multi-storey,
leaf_sharing/co_type, true skew-quad regions). Kept as a reference spike,
same status as experiments/autodiff_spike.py (§34); production wiring
into driver.py filed as homemaker-py-6xh.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LSwQwpEaHFBkeVSDDWd75S
