mistat (version 0.999)

mahalanobisT2: Mahalanobis $T^2$

Description

Mahalanobis $T^2$ and Confidence Region

Usage

mahalanobisT2(x, factor.name, response.names = names(x)[!names(x) %in% factor.name], 
conf.level=0.95, compare.to = NA, plot = FALSE)

Arguments

x

a data frame

factor.name

single character indicating column name of the experiment factor to test, the first level is used as a reference

response.names

vector of characters indicating columns names of the responses

conf.level

confidence level for the Confidence Region

compare.to

a vector of length length(response.names) to be compared to the result in terms of Mahalanobis $T^2$

plot

logical, if TRUE also a plot is produced

Value

• a list with components:
• coord
  matrix with transformed coordinates of variables in response.names
• mahalanobis
  vector containing Lower Control Region, Center and Upper Control Region of Mahalanobis $T^2$
• mahalanobis.compare
  single value, Mahalanobis $T^2$ of compare.to

References

Kenett, R., Zacks, S. with contributions by Amberti, D. Modern Industrial Statistics: with applications in R, MINITAB and JMP. Wiley. Tsong et al, (1996).

Examples

data(DISS)

mahalanobisT2(DISS[, c("batch", "min15", "min90")], 
              factor.name="batch", 
              conf.level=0.90,
              compare.to=c(15, 15))