stats.T2.single: Statistics used in computing and drawing the Hotelling T^2 chart for individual observations data
Description
These functions are used to compute statistics required by the $T^2$ chart for individual observations.Usage
stats.T2.single(data, center = NULL, cov = NULL)limits.T2.single(ngroups, size, nvars, conf)
Arguments
data
the observed data values
center
a vector of values to use for center of input variables.
cov
a matrix of values to use for the covariance matrix of input variables.
conf
confidence level (0 < conf < 1)
Value
- The function
stats.T2.single returns a list with components: - statisticsa vector of values for the $T^2$ statistic
- meansa matrix of within group means for each variable (which is equal to
data since sample are of sizes one) - centersample/group center statistic
- Scovariance matrix
- The function
limits.T2.single returns a list with components: - controlcontrol limits
- predictionpred.limits
References
Mason, R.L. and Young, J.C. (2002) Multivariate Statistical Process Control with Industrial Applications, SIAM.
Montgomery, D.C. (2005) Introduction to Statistical Quality Control, 5th ed. New York: John Wiley & Sons.
Ryan, T. P. (2000), Statistical Methods for Quality Improvement, 2nd ed. New York: John Wiley & Sons, Inc.