SPCDataModel-class: Data Model for SPC charts
In spcadjust: Functions for Calibrating Control Charts

Description Details See Also

This is the basic structure for converting observations (data) into updates for control charts. Classes of this type also have the ability to generate new data sets (resampling).

Every element of this class has to consist of a list of the following functions: updates, getcdfupdates, Pofdata, resample, xiofP, which have to be of a specific form. The arguments generally have the following meaning: xi denotes the parameter vector needed to create updates for running the chart from observed data, data is observed data, P is a data model.

updates(xi,data): Returns updates for the chart using the parameter xi and the observed data data.
Pofdata(data): Estimates a probability model from the data.
xiofP(P): Computes the parameter xi needed to compute updates from an (estimated) probability model P.
resample(P): Generates a new data set from the probability model P.
getcdfupdates(P,xi,cadlag=TRUE): Returns the cumulative distribution function (CDF) of updates of data generated from the probability model P and computed using the parameter xi. The CDF has to be a function of one argument that also accepts vectors. If cadlag is TRUE then the CDF is right-continuous (i.e. F(x)=P(X≤ x)). If cadlag is FALSE then the CDF is left-continuous (i.e. F(x) = P(X<x)).