pub struct NonNormalCapabilityResult {
pub lambda: f64,
pub lambda_at_bound: bool,
pub indices: Option<CapabilityIndices>,
}Expand description
Result of a Box-Cox-based non-normal capability analysis.
Fields§
§lambda: f64The estimated optimal Box-Cox transformation parameter λ.
λ ≈ 0 corresponds to a log transform; λ = 1 is the identity (no transform); λ = 0.5 is approximately a square-root transform.
lambda_at_bound: booltrue when the likelihood maximum lies on an end of the λ search range:
the likelihood was still rising there, so lambda is that range limit
(exactly) rather than an interior estimate, and the transformed-scale
indices are computed at a λ the data did not choose. Widen the range to
find the unconstrained optimum.
indices: Option<CapabilityIndices>Capability indices computed on the Box-Cox-transformed scale, or None
when no specification limit was given (the transform alone was asked
for).
Only the long-term indices (pp, ppk, ppu, ppl) are reported.
cp, cpk, cpu and cpl are always None: they are defined against
a within-subgroup sigma, and a flat observation vector carries no
subgroup structure to estimate one from. cpm follows its usual rule
(both limits and a target, on the transformed scale).