Trust / Validation

Formula Tests and Change Log

The current engine passed 26 automated tests and 17 independent mathematical cross-checks before design expansion.

Representative fixtures

Flat: rise 0, run 12 → 0°, 0%, multiplier 1. 6/12 → 26.565051°, 50%, multiplier 1.118033989. 12/12 → 45°, 100%, multiplier 1.414213562.

Metric equivalence: rise 0.5 m, run 1 m matches 6/12. Rafter: run 4 m at 6/12 → 4.472135955 m. Area: plan 100 m² at 6/12 → 111.8033989 m².

Failure-state coverage

Tests reject zero or negative run, negative dimensions, blank fields, ambiguous numbers, impossible triangles, excessive section counts and overflow. Repeated conversion stays within the documented tolerance.

Change log

rgw-core 0.1.0-gate2 — 4 September 2026: initial frozen formula contract and fixtures. No later formula changes are recorded.

Published validation register

IDCalculator / modeInputsExpected full precisionExpected displayToleranceStatus
P-001Pitch / rise-run6 in, 12 in26.565051177°26.57°1e-12Pass
P-002Pitch / flat0 m, 4 mfactor 11.00000Pass
C-001Converter / degrees45°12/1212.0000/121e-12Pass
R-001Rafter / run4 m, 6/124.472135955 m4.472 m1e-9Pass
R-002Rafter / deduction1 ft run, 3 ft ridgeerrorvisible alertexactPass
A-001Area / gable10×8 m, 6/1289.4427191 m²89.44 m²1e-8Pass
F-001Factor / 12/1212/121.4142135621.414213561e-12Pass
T-001Triangle / legs8, 15slope 1717.0001e-12Pass
T-002Triangle / impossiblerise 5, slope 4errorvisible alertexactPass
M-001Material / zero waste100 m², 0%, 333.333333 units34 units1e-9Pass
U-001Units / length1 ft0.3048 m0.3048 m0Pass
U-002Units / area1 ft²0.09290304 m²0.09290304 m²0Pass

Test date: 4 September 2026. Engine: rgw-core 0.2.0. The automated suite also covers blank, negative, non-finite, ambiguous-format, maximum-count and conversion-round-trip states.

Change log

rgw-core 0.2.0 — 4 September 2026. Added exact interactive length and area conversion, six-pair triangle unit qualification, staged rafter adjustments, configurable material-unit naming and auditable multi-section exports. Added unit, invalid-deduction, zero-waste and record-total regressions.

rgw-core 0.1.0-gate2 — 4 September 2026. Established the initial formula contract for pitch, factor, simple rafter line, compatible plan area and right-triangle fixtures.

Reviewed 4 September 2026Calculation version rgw-core 0.2.0