rat: Weight gain in rats exposed to thiouracil and thyroxin

In ALA: Data sets and examples for the book "Applied Longitudinal Analysis"

Description

The data are from a study of weight gain, where investigators randomly assigned 30 rats to three treatment groups.

Usage

data(rat)

Format

A data frame with 135 observations on the following 4 variables.

id

a factor with 27 levels

treatment

a factor with levels control, thiouracil, and thyroxin

week

a numeric vector

weight

a numeric vector

Details

The data are from a study of weight gain, where investigators randomly assigned 30 rats to three treatment groups: treatment 1 was a control (no additive); treatments 2 and 3 consisted of two different additives (thiouracil and thyroxin respectively) to the rats drinking water. Weight was measured at baseline (week 0) and at weeks 1, 2, 3, and 4.

Note

Original variable names have been adapted to R conventions. Data were reshaped from wide to long format and the response named weight.

Due to an accident at the beginning of the study, data on 3 rats from the thyroxin group are unavailable.

Source

http://biosun1.harvard.edu/~fitzmaur/ala

References

Box GEP (1950) Problems in the analysis of growth and wear curves. Biometrics 6:362-389

Examples

str(rat)
summary(rat)

ALA documentation built on May 2, 2019, 5:39 p.m.