ratpup {WWGbook}R Documentation

ratpup data in Chapter 3

Description

The data come from a study in which 30 female rats were randomly assigned to receive one of three doses (High, Low, or Control) of an experimental compound.

Usage

data(ratpup)

Format

A data frame with 322 observations on the following 6 variables.

pup.id
: Unique identifier for each rat pup
weight
: Birth weight of the rat pup (the dependent variable)
sex
: Sex of the rat pup (Male, Female)
litter
: Litter ID number
litsize
: Litter size (i.e., number of pups per litter)
treatment
: Dose level of the experimental compound assigned to the litter (High, Low, Control)

References

Pinheiro, J.C. and Bates, D.M., Mixed-effects models in S and S-PLUS, Springer-Verlag Inc., Berlin, New York, 2000.

West, B., Welch, K. & Galecki, A, Linear Mixed Models: A Practical Guide Using Statistical Software, Chapman Hall / CRC Press, first edition, 2006.

Examples

attach(ratpup)

###Figure 3.1:Boxplots to compare the distributions of birth weights for each treatment by sex combination graphically
library(lattice)  # trellis graphics
library(grid)

bwplot(weight ~ sex|treatment, data=ratpup,aspect = 2, ylab="Birth Weights", 
    xlab="SEX",main = "Boxplots of birth weights for levels of treatment by sex")

[Package WWGbook version 1.0.0 Index]