clFun {qAnalyst} | R Documentation |
clFun
calculates upper and lower confidence limits for control charts. Confidence limits are retuned as a vector.
clFun(x, sg, nSigma, cl, type = "xbar")
x |
data vector |
sg |
subgroup id for variable chart, subgroups dimension for variables chart, moving window interval in i / mr chart. A detailed description of sg field is in spc function help. |
nSigma |
number of standard deviations from the center line |
cl |
"u" or "l" respectively for upper or lower confidence limit |
type |
type of control chart |
clFun allows to handle unequal sample size subgroups that makes confidence limits to vary. A warning is thrown if subgroup dimension is less than 2 when variables chart for groups are calculated.
A vector of length equal to the number of points in the chart representing either lower o upper confidence limit.
Internal function
Andrea Spano' and Giorgio Specicato
Montgomery, Statistical Quality Control
#brakeCap dataset data(brakeCap) clFun(x=brakeCap$hardness, sg=brakeCap$subgroup, nSigma=2, cl="u", type="xbar")