ToothGrowth
The Effect of Vitamin C on Tooth Growth in Guinea Pigs
The response is the length of odontoblasts (cells responsible for tooth growth) in 60 guinea pigs. Each animal received one of three dose levels of vitamin C (0.5, 1, and 2 mg/day) by one of two delivery methods, (orange juice or ascorbic acid (a form of vitamin C and coded as VC
).
Usage
ToothGrowth
Format
A data frame with 60 observations on 3 variables.
[,1] | len | numeric | Tooth length |
[,2] | supp | factor | Supplement type (VC or OJ). |
[,3] | dose | numeric | Dose in milligrams/day |
Source
C. I. Bliss (1952) The Statistics of Bioassay. Academic Press.
References
McNeil, D. R. (1977) Interactive Data Analysis. New York: Wiley.
Crampton, E. W. (1947) The growth of the odontoblast of the incisor teeth as a criterion of vitamin C intake of the guinea pig. The Journal of Nutrition 33(5): 491–504. http://jn.nutrition.org/content/33/5/491.full.pdf
Examples
require(graphics) coplot(len ~ dose | supp, data = ToothGrowth, panel = panel.smooth, xlab = "ToothGrowth data: length vs dose, given type of supplement")