Python rewrite of the Urb/Homemaker stack
Bruno Postle
65085d5c3d
When a compound operator (e.g. level_compound_fix) creates a new internal node and explicitly sets its division ratio, that ratio was silently overridden: warm_x0 received parent.ratios which had no entry for the new node, so Nelder-Mead started at the default 0.5 instead of the operator's intended 0.25 (for rrl/rrr). Result: NM evaluated the compound topology at the wrong geometry and scored 3 fails instead of 1 — so lex always rejected the compound child, making level_compound_fix invisible to the outer search. Fix: for nodes that are genuinely newly divided (not divided in the parent tree at the same path), inherit the child's operator-set ratio rather than defaulting to 0.5. Structural mutations (e.g. swap) can reveal hidden level-N nodes that retain stale pre-writeback ratios — those are correctly excluded by checking parent_node.divided. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> |
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|---|---|---|
| .beads | ||
| .claude | ||
| examples | ||
| experiments | ||
| src/homemaker_layout | ||
| tests | ||
| .gitignore | ||
| AGENTS.md | ||
| CLAUDE.md | ||
| DESIGN.md | ||
| pyproject.toml | ||
| README.md | ||
homemaker-layout
Programme-driven building-layout search over slicing trees. A clean-room Python successor to the Perl Urb project, intended to eventually be 100% Python.
Why a rewrite
Urb represents a building as a binary slicing tree where room sizes are derived top-down from division ratios. That makes room area an emergent property of every cut above it, which:
- gives the genome low locality (a cut near the root rescales every descendant),
- makes target room sizes nearly impossible to hit, so the gaussian size penalty dominates fitness, and
- defeats crossover (transplanted subtrees lose their proportions).
homemaker inverts this: leaves carry target dimensions from the programme and division ratios are solved bottom-up for a fixed topology. The evolutionary search then only explores topology + types + adjacency.
Phase plan
- Solver experiment (current): port Urb's geometry, re-solve ratios from programme targets, score the result against the original via the Perl oracle.
- Native Python fitness (retire the Perl oracle).
- Canonical slicing encoding (normalized Polish expression) + memetic search.
Layout
src/homemaker_layout/dom.py— read/write Urb.domYAML into aNodetree.src/homemaker_layout/geometry.py— faithful port of Urb's top-down geometry.src/homemaker_layout/programme.py— parsepatterns.configspace requirements.src/homemaker_layout/solver.py— bottom-up ratio solve (scipy).src/homemaker_layout/oracle.py— Phase-1 scaffold: score a.domvia Urb'surb-fitness.pl.
The Perl oracle is the only throwaway component; everything else is permanent.