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

1. Solver experiment: port Urb's geometry, re-solve ratios from programme targets, score the result against the original via the Perl oracle. ✓
2. Native Python fitness (retire the Perl oracle). ✓
3. Memetic search: canonical slicing genome + high-locality operators + Nelder-Mead inner loop. ✓
4. Penalty reshaping: lexicographic (-n_fails, fitness) outer-search comparison. ✓
5. Representation upgrade: canonical slicing encoding + bottom-up shape feasibility, scaled to larger programmes. ✓
6. Search-quality experiments (current): a long running series of opt-in levers tried against the harbor-house, health-centre, and programme-house example corpora — leaf-sharing, finish-time cell→room collapse, ruin-and-recreate LNS, 2-opt polish, multi-use/co-located leaves, adjacency-graph and bubble-diagram fitness signals, and more. Most of these are negative/null results kept as opt-in flags or reference code rather than defaults. See DESIGN.md §11 onward for the full, numbered experiment log with methodology and results for each.

Layout

• src/homemaker_layout/dom.py — read/write Urb .dom YAML into a Node tree.
• src/homemaker_layout/geometry.py — faithful port of Urb's top-down geometry.
• src/homemaker_layout/programme.py — parse patterns.config space requirements.
• src/homemaker_layout/solver.py — bottom-up ratio solve (scipy).
• src/homemaker_layout/fitness.py — native Python fitness evaluator.
• src/homemaker_layout/fitness_cmd.py — homemaker-fitness CLI (drop-in for urb-fitness.pl).
• src/homemaker_layout/collapse_cmd.py — homemaker-collapse CLI: finish-time global cell→room relabel of a .dom.
• src/homemaker_layout/graph.py — leaf-adjacency graph for programme-driven checks.
• src/homemaker_layout/genome.py — topology genome: base-floor tree + per-storey deltas.
• src/homemaker_layout/operators.py — high-locality mutation and subtree crossover.
• src/homemaker_layout/innerloop.py — ratio optimisation inner loop (Nelder-Mead / CMA-ES).
• src/homemaker_layout/driver.py — memetic search outer loop.
• src/homemaker_layout/evolve.py — homemaker-evolve CLI entry point.
• src/homemaker_layout/oracle.py — legacy Perl shim, kept for cross-validation only.
• src/homemaker_layout/bubble.py — 3D bubble-diagram adjacency fitness-signal prototype (DESIGN.md §27); validated null, not wired into fitness.py — reference only.

Room codes and reserved names

Leaf types live in three namespaces that share a first character. Only the first is enforced; the other two are conventions the fitness function reads, so a room's spelling can change how it is scored.

1. Generic structural types — C, O, S (reserved). The leaves the search itself creates: C circulation, O outside, S sahn (an outside court that also serves as circulation). Always uppercase. A programme code spelled exactly C, O or S is rejected at load.

2. Programme room codes — anything else, lowercase. k1, b1, cr1, of, and single-character codes like r or t. These may start with any letter: since DESIGN.md §39.4 the generic tests match C/O/S exactly, so naming a room cr1 no longer makes it circulation. (Before that fix it did — and silently dropped it from the required-space check entirely.)

3. Access requirements — the usage: attribute. Every space declares one of living, kitchen, bedroom, toilet, utility, none. Mandatory, no fallback, and a missing or unknown value is a load error. It replaced a first-character convention (b/t/l/k) under which a room silently inherited another room's connectivity rules from its spelling — la1 "Laundry Room" was trimmed as a living room (DESIGN.md §39.7).

spaces:
  la1:
    usage: utility          # controlled, drives engine behaviour
    name: Laundry Room      # free text, building-specific

A usage value exists only where the engine treats it differently, so the vocabulary is closed: a new access class means new code, not new config. Check a programme with:

python experiments/audit_programme_config.py

which reports reserved-name collisions, the usage class each code picks up, and whether each room's size/width/proportion/crinkliness targets are mutually satisfiable at all.