sBar {ggQC}

Mean Subgroup Standard Deviation

Description

Calculates the mean subgroup standard deviation used when constructing a XbarS chart.

Usage

sBar(data, value, grouping, formula = NULL, ...)

Arguments

data

data frame to be processed

value

numeric vector in a data frame with values of interest.

grouping

single factor/variable to split the data frame "values" by.

formula

a formula, such as y ~ x1 + x2, where the y variable is numeric data to be split into groups according to the grouping x factors/variables

...

further arguments passed to or from other methods.

Value

A number; mean subgroup standard deviation.

Examples

set.seed(5555)
df <- data.frame(v=rnorm(60, 0, 1), g=rep(c("A","B","C","D","E"), each=12))
sBar(data = df, formula = v~g)