XploRe Help : spccusumCc

Keywords - Function groups - @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Library:	spc
See also:	spccusumCarl spccusum2c

Quantlet:		spccusumCc
Description:		Computes the critical value of the Crosier-CUSUM chart for given in-control Average Run Length. The data is normally distributed with variance 1.

Reference(s):

Crosier, R.B. (1986). A new two-sided cumulative quality control scheme. Technometrics 28: 187-194

Usage:	`c = spccusumCc (ARL, k, r)`
Input:
	`ARL`	scalar, representing a user-defined in-control Average Run Length of a Crosier-CUSUM chart
	`k`	scalar, reference value. It must be positive and be expressed as a multiple of the standard error.
	`r`	scalar, matrix dimension of the approximating two-dimensional Markov chain
Output:
	`c`	scalar, critical value of a Crosier-CUSUM chart with user-defined in-control ARL

Note:

The algorithm is based on the Brook/Evans approach and regula falsi.

Example:

; critical value c of the Crosier-CUSUM chart with ; in-control ARL = 100, reference value k = 0.5 ; and matrix dimension 50(of the approximating two- ; dimensional Markov chain): library("spc") c = spccusumCc(100, 0.5, 50) c

Result:

Contents of c
[1,]   3.2435

Example:

library("spc") c = spccusumCc(100, 0.25, 50) c

Result:

Contents of c
[1,]   4.8922

Author: S. Knoth, 20011010 license MD*Tech