X-bar Shewhart Control Chart for phase I.

Source: R/cchart.Xbar1.R

Builds the x-bar control chart for phase I.

cchart.Xbar1(x, sizes)

Arguments

x

The data to be plotted.

sizes

A value or a vector of values specifying the sample sizes associated with each group.

Value

Returns a list with the mean of means (x2bar) and the standard deviation (sigma), invisibly. Also plots the control chart as a side effect.

Details

Even if the data is not normal the x-bar statistic will be close to the normal by the central limit theorem.

See also

cchart.Xbar2

Author

Daniela R. Recchia, Emanuel P. Barbosa

Examples


data(pistonrings)
cchart.Xbar1(pistonrings[1:25, ], 5)