control.limits.x {envoutliers}  R Documentation 
Estimation of limits of control chart x. The function is called by KRDetect.outliers.controlchart
and is not intended for use by regular users of the package.
control.limits.x(x, method = "range", group.size, L)
x 
a numeric vector of data values. 
method 
a character string specifying the preferred estimate of standard deviation parameter. Possible options are

group.size 
a positive integer giving the number of observations in individual segments used for computation of control chart limits. If the data can not be equidistantly divided, the first extra values will be excluded from the analysis. 
L 
a positive numeric value giving parameter 
This function computes parameters based on which control chart x can be constructed. The function is exported for developer use only. It does not perform any checks on inputs since it is only a convenience function for identification limits based on control chart x.
A list is returned with elements:
x 
a numeric vector of data 
mean 
a numeric value giving sample mean of vector 
groups.count 
a numeric value giving a number of segments used for estimating parameters of control chart 
groups.mean 
a numeric vector giving sample means in individual segments used for estimating parameters of control chart 
LCL 
numeric value giving lower control limit of control chart x 
UCL 
numeric value giving upper control limit of control chart s 
Shewhart W (1931). Quality control chart. Bell System Technical Journal, 5, 593–603.
SAS/QC User's Guide, Version 8, 1999. SAS Institute, Cary, N.C.
Wild C, Seber G (2000). Chance encounters: A first course in data analysis and inference. New York: John Wiley.