capabilityNormal {qAnalyst} | R Documentation |
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.
capabilityNormal(x, sg=length(x), lsl = NULL, usl = NULL, target = NULL, name = deparse(substitute(x)), toler=6, historicalMean=NA, historicalSd=NA)
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 |
Either lsl or usl must be specified.
An object of class capability
No notes
Andrea Spano'
Bothe (1997), Measuring Process Capability, McGraw Hill
plot.capability
, print.capability
, summary.capability
data(brakeCap) capObj=capabilityNormal(x=brakeCap$hardness,sg=brakeCap$subgroup, lsl=39, usl=41, target=40, name="HARDNESS") summary(capObj)