Elamur Groupantsmlab-builtins-stats-ols
The groupant beside mlab/src/builtins/stats.rs in the Mova repository: what the code computes, what it never does, how to go back from its outputs, its invariants, cost and checks.
Facts
Implementation material. A Mova code model describes this code at one source revision: partial models, finite checks and their stated scope. It is not a reviewed general exposition, and its labels are shown as written, never raised.
Components
| component | label | where |
|---|---|---|
| approximant | partial | approximant |
| ast | partial | ../syntax.json |
| cost | symbolic source derived | invariant |
| descriptant | present | descriptant |
| invariant | partial | invariant |
| tests | partial bounded parent evidence | tests |
Obernants
The typed relations around the forward model: the behaviour complement (what the code never does), the reverse reconstruction (every input compatible with an output) and specialised views.
| id | type | label | where |
|---|---|---|---|
behavior_complement | behavior_complement | partial source derived model | behavior_complement |
reverse_reconstruction | reverse_reconstruction | partial source derived model | reverse_reconstruction |
rank_boundary | rank_boundary | partial source derived model | rank_boundary |
formula_transport | formula_transport | partial source derived model | formula_transport |
branch_relation | branch_relation | partial source derived model | branch_relation |
resource_cost | resource_cost | partial source derived model | resource_cost |
Model text
descriptant
mlab-builtins-stats-ols
ols rejects n<=p, then Householder QR with rank threshold1e-12*max running norm; solves upper triangle and inverse for SE, residual metrics. fitlm drops rows with any NaN, prepends ones optionally, compares beta against mldivide relative norm with floor1e-300 and warns above1e-8.
Epoch 2026-10-31: isolated source-bound fragment over bytes [37102,47343); includes no claim beyond this relation. Source hash bdc3772b09d9113e108afa29e391fee97a5372caf9052bb1689996c41c94116f.
approximant
ols: forward relation
ols rejects n<=p, then Householder QR with rank threshold1e-12*max running norm; solves upper triangle and inverse for SE, residual metrics. fitlm drops rows with any NaN, prepends ones optionally, compares beta against mldivide relative norm with floor1e-300 and warns above1e-8.
Domain: Finite, well-shaped bounded observations unless branch explicitly describes NaN/Inf. Direct public chi2/OLS helpers assume dimensions not checked at every index; wrappers add validation.
Executable surrogate gap: no measured cheaper implementation with a useful scoped metric is supplied. Categorical/error/effect relations are exact obligations, not percent losses. Future numeric caps only1/2/5/10%.
invariant
ols: invariant and cost
Rank judged without pivoting and running norm; first n<=p failure excludes QR iteration.
parse_formula admits additive names, 1/-1/0 toggles intercept; repeated names retained and can cause rank deficiency; formula validates response last.
Scope-specific cost: Householder O(np²) plus inverse O(p³), O(np+p²) memory; wrapper additionally solves independent mldivide and formats O(p) coefficient rows.
models
behavior_complement
Gate warning does not prevent returning coefficients. No unique inverse from beta to dataset; exact fit can produce zero SE and infinite t. Malformed column lengths can panic.
reverse_reconstruction
beta compatible with every (X,y) whose finite QR solve yields beta, including y=Xbeta+residual orthogonal to design; original dropped NaN rows unidentifiable.
rank_boundary
Rank judged without pivoting and running norm; first n<=p failure excludes QR iteration.
formula_transport
parse_formula admits additive names, 1/-1/0 toggles intercept; repeated names retained and can cause rank deficiency; formula validates response last.
branch_relation
ols rejects n<=p, then Householder QR with rank threshold1e-12*max running norm; solves upper triangle and inverse for SE, residual metrics. fitlm drops rows with any NaN, prepends ones optionally, compares beta against mldivide relative norm with floor1e-300 and warns above1e-8.
resource_cost
Householder O(np²) plus inverse O(p³), O(np+p²) memory; wrapper additionally solves independent mldivide and formats O(p) coefficient rows.
tests
Evidence boundary
See ../tests.md for the actual selected source test and mutant. These tests sample the file, not every fragment branch. Gate warning does not prevent returning coefficients. No unique inverse from beta to dataset; exact fit can produce zero SE and infinite t. Malformed column lengths can panic. Other branches here are source-derived and unexecuted unless the parent test explicitly calls them.
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