mouse.c {bootstrap}

Experiments with mouse

Description

A small randomized experiment were done with 16 mouse, 7 to treatment group and 9 to control group. Treatment was intended to prolong survival after a test surgery.

Usage

data(mouse.c)

Format

The format is: num [1:9] 52 104 146 10 50 31 40 27 46

Details

The treatment group is is dataset mouse.t. mouse.c is the control group. The book uses this example to illustrate bootstrapping a sample mean. Measurement unit is days of survival following surgery.

Source

Efron, B. and Tibshirani, R. (1993) An Introduction to the Bootstrap. Chapman and Hall, New York, London.

Examples

str(mouse.c)
if(interactive())par(ask=TRUE)
stripchart(list(treatment=mouse.t, control=mouse.c))
cat("bootstrapping the difference of means, treatment - control:\n")
cat("bootstrapping is done independently for the two groups\n")
mouse.boot.c <- bootstrap(mouse.c, 2000, mean)
mouse.boot.t <- bootstrap(mouse.t, 2000, mean)
mouse.boot.diff <- mouse.boot.t$thetastar - mouse.boot.c$thetastar
hist(mouse.boot.diff)
abline(v=0, col="red2")
sd(mouse.boot.diff)