capabilityNormal {qAnalyst} | R Documentation |
capabilityNormal
function creates capability class object for normal data given specification limits. plot
, print
, 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, histPars=c(NA,NA))
x |
a 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 dimension. Default is sg=length(x), that means there are no subgroups. |
lsl |
lower specification limit. |
usl |
upper specification limit. |
target |
process target. |
name |
name of the variable, default taken by "x" name. |
toler |
width of tolerance specification. Default is 6, that is six sigma |
histPars |
a vector of two elements that allows user to specify historical mean and standard deviation respectively |
Either lsl or usl must be specified. capabilityNormal
is a wrapper of many internal functions, that check user specifications consistency and perform calculation of statistics. Results are stored into a capability object.
A capability object list is returned
It creates the core capability objects
Giorgio Spedicato
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)