centerFun {qAnalyst}R Documentation

Internal function to calculate center line values

Description

centerFun calculates and returns the center line constant for the given chart type.

Usage

centerFun(x, sg, type = "xbar", mu = NA, sigma = NA)

Arguments

x

data vector.

sg

subgroups id for variables chart, subgroups dimension for attributes chart, interval dimension for i/mr chart. A detailed description of sg field is in spc function help.

type

chart type.

mu

A scalar containing the process mean. Its use will be different depending from chart type. For more details see spc.

sigma

A scalar containing the process within samples standard deviation. For more details see spc.

Details

centerFun calculates the center line value. Formulas used are taken from quoted reference book.

Value

A numeric value for the center line.

Note

centerFun is called internally by spc.

Author(s)

Andrea Spano' and Giorgio Spedicato

References

Montgomery, Statistical Quality Control

See Also

spc, clFun

Examples

#brakeCap dataset
data(brakeCap)
centerFun(x=brakeCap$hardness, sg=brakeCap$subgroup, type="xbar")

[Package qAnalyst version 0.6.4 Index]