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
Examples
#a simple example
getParameterFun(5,"d2")
[Package qAnalyst version 0.6.4 Index]