getq {spcadjust}

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)

## S4 method for signature 'SPCCUSUM'
getq(chart, property, params)

## S4 method for signature 'SPCEWMA'
getq(chart, property, params)

## S4 method for signature 'SPCShew'
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.