Public evidence

engineering.msa.linearity

Machine-checked verification for calculation version 1.0.0 · tier engine_tested

Open calculator API Capability Download JSON MCP Review policy

Verification

9/9 calculation tests · Production surface contract 4/4

Golden tests 0 / 0
Boundary tests 6 / 6
Property tests 3 / 3
Production surface contract 4 / 4
Engine tested Yes
Source checked Yes
Artifact integrity PASS
Production attestation Embedded snapshot: unpublished · Build schema 1.0.0 ready · Semantic contract ✓ · Attestation report not published on origin · Live production status STALE (1 capability; 156 remain CURRENT) @ 2026-09-14T03:54:53.650Z
Semantic contract PASS
Evidence attested at 2026-09-14T00:43:05.498Z
Last production check 2026-09-14T00:43:05.498Z
Public / cache —
Origin —
Supplemental domain review Not performed
Named expert review Not performed

release artifacts aligned PASS
schema valid input executes PASS
engine success output validates schema PASS
schema rejects incomplete input PASS

Fingerprint sha256:257ca7997ec399f806a68a89ee72fe6fadd91ff7cca3f947efd72a26820c25f8

Input schema sha256:cc2a36f22622cc63033e0c726aba51a3fd0aec3694e4f8528f433b769d5f6eaf · Output schema sha256:33668072c4df3c6ea841a5a439f5f501eee69e1c14e87453dfa9a9b09294404b · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Build & scope

Engine identity and declared limitations.

Tool: linearity
Engine: linearity
Engine build: 2026-09-15
Evidence core: 2026-09-15T22:10:24.430Z
Rendered: 2026-09-15T23:38:12.911Z
Last reviewed: —

Assumptions

Ordinary least squares of ε = ylab − xref versus xref. slope = dε/d(xref).
n≥3 paired points. xref must not all be equal.
Not a single-master bias, not Type-1 Cg/Cgk, and not a %Linearity pass/fail.
Does not take T.

Limitations

Ordinary least squares of ε versus xref — not a %Linearity / process-variation verdict
Not a single-master bias (Accuracy) and not Type-1 Cg/Cgk
Does not take T and does not issue pass/fail
n≥3 paired points; xref must not all be equal

Sources

Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.

AIAG Measurement Systems Analysis (MSA) — Linearity and bias study — error versus reference
Supports: Linearity is the change of bias across the operating range. This page reports the OLS slope of ε versus xref and does not issue a %Linearity verdict.
ISO 11095 — Linear calibration using reference materials — Ordinary least squares of response versus reference
Supports: Paired reference and indication values; linear fit. This page fits ε versus xref rather than ylab versus xref.

Published checks

Golden, boundary, and property cases included in this evidence build.

ID	Kind	Status	Detail
`boundary-lin`	boundary	pass	Expected n=3 · slope=0.5 · intercept=0 · r_squared=1 · Actual n=3 · slope=0.5 · intercept=0 · r_squared=1 · xbar=2 · ebar=1
`boundary-lin-flat`	boundary	pass	Expected slope=0 · intercept=1 · Actual n=3 · slope=0 · intercept=1 · xbar=2 · ebar=1
`boundary-lin-n2`	boundary	pass	Expected VALUE_OUT_OF_RANGE · Actual VALUE_OUT_OF_RANGE
`boundary-lin-equal`	boundary	pass	Expected INVALID_INPUT · Actual INVALID_INPUT
`boundary-lin-len`	boundary	pass	Expected INVALID_INPUT · Actual INVALID_INPUT
`boundary-lin-missing`	boundary	pass	Expected MISSING_REQUIRED_INPUT · Actual MISSING_REQUIRED_INPUT
`property-lin`	property	pass	0.5
`property-lin-flat`	property	pass	0
`property-lin-alias`	property	pass	0.5