SigmaEstimator Enumeration

Specifies the method used to estimate process variation for within-process sigma calculations.

Definition

Namespace: Numerics.NET.Statistics.ProcessControl
Assembly: Numerics.NET (in Numerics.NET.dll) Version: 10.4.0
C# 
public enum SigmaEstimator

Remarks

The estimator chosen must be compatible with the input data shape and the computation being performed. Incompatible combinations are rejected immediately; no silent fallback is performed.

Valid estimators by data shape:

  • Individuals data: MovingRange and OverallStandardDeviation.
  • Subgrouped data: WithinRange, WithinStandardDeviation, PooledVariance, and OverallStandardDeviation.

Members

OverallStandardDeviation0 Estimates sigma from the overall sample standard deviation of all observations. Valid for both individuals and subgrouped data.
WithinRange1 Estimates within-subgroup sigma from subgroup ranges and the appropriate SPC constant. Requires subgroup size of at least 2. Intended for subgroup-based capability analysis and XBar–R chart calculations.
WithinStandardDeviation2 Estimates within-subgroup sigma from subgroup standard deviations and the appropriate SPC constant. Requires subgroup size of at least 2. Intended for subgroup-based capability analysis and XBar–S chart calculations.
PooledVariance3 Estimates within-subgroup sigma from pooled subgroup variance. Requires subgroup size of at least 2.
MovingRange4 Estimates sigma from moving ranges of successive observations. Intended primarily for individuals data. Not valid for subgroup-based chart factories in Phase 1.

See Also