This function builds a S control chart.

cchart.S(x, type = "n", m = NULL)

Arguments

x

The data to be plotted.

type

A character string specifying the type of S control chart to be plotted where "n" plots a S chart with normalized probability limits and "e" plots a S chart with exact limits.

m

The sample sizes. Only necessary in the control chart with exact (probability) limits.

Value

Return a S control chart.

Details

The exact limits are the alpha/2 and 1-alpha/2 quantiles of the S distribution which is proportional to the square root of a chi-square distribution.

Examples

data(softdrink) #S chart with normalized probability limits cchart.S(softdrink, type = "n")
#> List of 11 #> $ call : language qcc(data = x, type = "S") #> $ type : chr "S" #> $ data.name : chr "x" #> $ data : num [1:15, 1:10] 2.5 0 1.5 0 0 1 1 0 -2 -0.5 ... #> ..- attr(*, "dimnames")=List of 2 #> $ statistics: Named num [1:15] 1.333 0.926 1.125 1.174 0.471 ... #> ..- attr(*, "names")= chr [1:15] "1" "2" "3" "4" ... #> $ sizes : int [1:15] 10 10 10 10 10 10 10 10 10 10 ... #> $ center : num 1.09 #> $ std.dev : num 1.12 #> $ nsigmas : num 3 #> $ limits : num [1, 1:2] 0.31 1.88 #> ..- attr(*, "dimnames")=List of 2 #> $ violations:List of 2 #> - attr(*, "class")= chr "qcc"
#S chart with exact probability limits cchart.S(softdrink, type = "e", 10)