capabilityNormal {qAnalyst}R Documentation

Computing Capability Analysis for Normal data

Description

capabilityNormal is used to compute capability analysis for normal distributed data. This function creates a capability class object for normal data. plot, print and summary methods are avaible for capability class objects.

Usage

capabilityNormal(x, sg=length(x), lsl = NULL, usl = NULL, target = NULL,
    name = deparse(substitute(x)), toler=6, historicalMean=NA, historicalSd=NA)

Arguments

x

Numeric data vector

sg

Subgroup specification. It represents rational sub-group of observations. It can be specified either as a vector, of the same length of x of ordered subgroup id, or as a constant indicating subgroup size. Default is sg=length(x).

lsl

Lower specification limit.

usl

Upper specification limit.

target

Process target.

name

Variable label to be used within graphics, default taken by "x" name.

toler

Width of tolerance specification. Default is 6

historicalMean

Mean of the population distribution if a known process parameter is available or an estimate obtained from past data. If mean value is not specified, it is estimated from data

historicalSd

Standard Deviation of the population distribution if a known process parameter is available or an estimate obtained from past data. If value of standard deviation is not specified, it is estimated from data

Details

Either lsl or usl must be specified.

Value

An object of class capability

Note

No notes

Author(s)

Andrea Spano'

References

Bothe (1997), Measuring Process Capability, McGraw Hill

See Also

plot.capability, print.capability, summary.capability

Examples

data(brakeCap)
capObj=capabilityNormal(x=brakeCap$hardness,sg=brakeCap$subgroup, lsl=39,
    usl=41, target=40,  name="HARDNESS")
summary(capObj)
  

[Package qAnalyst version 0.6.4 Index]