SSDforR (version 1.1)

Rchartsd: SPC R-chart using standard deviation

Description

The R-Chart is designed to detect changes in variation over time. This is one of two forms of the R-chart and should be used with samples larger than ten. This function uses the standard deviation of samples to track variation.

Usage

Rchartsd(behavior, groupX, bandX, ABxlab, ABylab, ABmain)

Arguments

behavior

behavior variable

groupX

grouping variable (e.g., day)

bandX

number of standard deviations desired (e.g., 2)

ABxlab

label for x-axis in quotation marks, (e.g., "day")

ABylab

label for y-axis in quotation marks (e.g., "amount")

ABmain

main title for graph in quotation marks (e.g., "Variation in Admits")

References

{Orme, J. & Cox, M.E. (2001). Analyzing single-subject design data using statistical proces control charts. Social Work Research, 25(2), 115-127.

} {Go to www.ssdanalysis.com for more information.}

Examples

admit<-c(85,90,80,84,82,79,75,76,80,84,75,80,79,83,88,78,80,85,83,82,89,84,89,91,87,84,77,86,80,
89,81,86,88,83,86,90,86,85,85,87,80,89,NA,86,87,88,89,79,73,75,74,70,75,81,85,75,73,75,
79,70,72,71,69,70,64,60,59,54,53,55,50,54,51,49,48,50,46,55,51,55,49,50,48,51,33)

day<-c(1,1,1,1,1,1,1,2,2,2,2,2,2,2,3,3,3,3,3,3,3,4,4,4,4,4,4,4,5,
5,5,5,5,5,5,6,6,6,6,6,6,6,NA,7,7,7,7,7,7,7,8,8,8,8,8,8,8,9,
9,9,9,9,9,9,10,10,10,10,10,10,10,11,11,11,11,11,11,11,12,12,12,12,12,12,12)

padmit<-c("A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A",
"A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A",
"A","A","A","A","A","A","A","A","A","A",NA,"B","B","B","B","B","B","B","B",
"B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B",
"B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B","B")
Rchartsd(admit, day, 2, "week", "amount", "Admits to Hospital")