Optionaloptions: {Optionalconfidence?: numberOptionallsl?: numberOptionalmethod?: "r" | "s"OptionalsigmaWithin?: numberExplicit within sigma from an independently fitted process estimator.
Optionalsubgroup?: numberOptionaltarget?: numberOptionalusl?: numberOptionalwithinDF?: numberEffective DF for approximate within-sigma confidence intervals.
Process capability indices (Minitab Capability Analysis — Normal). Within σ from R̄/d₂ (default) or S̄/c₄ when
method: 's'; overall σ = sample sd.