IQCC (version 1.0)

PextI: Exact (improved) p chart for phase I.

Description

This function builds an improved version (non-normal correction) of the p chart for phase I.

Usage

PextI(x, sizes,  par, length)

Arguments

x

The data to be plotted.

sizes

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

par

The data used to estimate the phat (x/sizes). This data is used only in this phase.

length

The length of the data.

Value

• Return an exact p chart.

Details

The non-normal correction considered is based on the Cornish-Fisher formula using cumulants until 3rd order.

References

Chen,G.(1998). An improved p chart through simple adjustment. Journal of Quality Technology, vol 30, pp 142-151.

See Also

PextII

Examples

data(binomdata)
attach(binomdata)
PextI(par=pi[1:12],x=Di[1:12],sizes=ni[1:12],length=12)