spcadjust (version 1.1)

getq: Returns a List to Compute Properties of a chart

Description

Returns functions to compute desired properties of a given control chart.

Usage

getq(chart, property, params)
"getq"(chart, property, params)
"getq"(chart, property, params)
"getq"(chart, property, params)

Arguments

chart

the chart to be used.

property

the name of the property.

params

additional parameters needed for the computations.

Value

A list with the elements q, trafo, lowerconf, format.

• q(P,xi): The transformed property of interest. To improve the bootstrap a log transform is used for calARL,calhitprob and ARL, and a logit transform for hitprob. This function depends on the distribution of updates P and the chart parameters xi.
• trafo(x): The inverse of the transformation of the property used in the bootstrap. Needed to back-transform the result to the correct scale.
• lowerconf: Logical value. TRUE if a lower confidence interval should be reported, FALSE otherwise. Default is TRUE for properties calARL, calhitprob and hitprob and FALSE for ARL.
• format(res): Output summary given as a text string.

Methods (by class)

• SPCCUSUM: Implements the properties ARL, calARL, hitprob and calhitprob.
• SPCEWMA: Implements the properties ARL, calARL, hitprob and calhitprob.
• SPCShew: Implements the properties ARL, calARL, hitprob and calhitprob.