getParameterFun {qAnalyst}R Documentation

Internal function to get control chart coefficients

Description

getParameterFun returns the value of a parameter given subgroup size and parameter name.

Usage

getParameterFun(n, parameter)

Arguments

n

subgroups length

parameter

string containing the name of parameters from A6 table, that is: "A", "A2", "A3", "c4", "c4rec", "B3", "B4", "B5", "B6", "d2", "d2rec", "D3", "D4", "D5", "D6".

Details

Tabulated values are used if subgroup size is less than 25. Otherwise, Montogmery SQC book's formulas are used.

Value

Value of the requested parameter given sample size.

warning

Montgomery original table does not report values for n=1. Constants "d2" and "d4" for n=1 have been integrated from Wheeler and Chambers (1992).

Note

No notes

Author(s)

Andrea Spano'

References

Montgomery, Statistical Quality Control; Wheeler and Chambers (1992). Undenstanding Statistical Process control

See Also

getCoeffFun

Examples

#a simple example
getParameterFun(5,"d2")

[Package qAnalyst version 0.6.4 Index]