MSQC (version 1.1.0)

covariance: Sample covariance

Description

It computes the sample covariance in presence of rational subgroups or for individual observations according to Sullivan and Woodall (1996) and Holmes and Mergen (1993)

Usage

covariance(x, stat, method, ...)

Arguments

x

matrix or array containing the quality characteristics.

stat

is the statistics

method

is the method used in individual observation case.

…

other parameters

References

Holmes, D.S., Mergen, A.E.: Improving the performance of T-square control chart. Quality Engineering 5(4), 619-625 (1993)

Sullivan, J.H., Woodall, W.H.: A Comparison of Multivariate Quality Control Charts for Individual Observations. Journal of Quality Technology 28(4) (1996)

Examples

# NOT RUN {
# individual case 
data(bimetal1)
covariance(bimetal1, method = "sw")
covariance(bimetal1, method = "hm")

# rational subgroup case
data(carbon1)
covariance(carbon1)
# }