Effectiveness of Insect Sprays

Description

The counts of insects in agricultural experimental units treated with different insecticides.

Usage

data(InsectSprays)

Format

A data frame with 72 observations on 2 variables.

[,1]	count	numeric	Insect count
[,2]	spray	factor	The type of spray

Source

Beall, G., (1942) The Transformation of data from entomological field experiments, Biometrika, 29, 243–262.

References

McNeil, D. (1977) Interactive Data Analysis. New York: Wiley.

Examples

require(stats)
data(InsectSprays)
boxplot(count ~ spray, data = InsectSprays,
        xlab = "Type of spray", ylab = "Insect count",
        main = "InsectSprays data", varwidth = TRUE, col = "lightgray")
fm1 <- aov(count ~ spray, data = InsectSprays)
summary(fm1)
opar <- par(mfrow = c(2,2), oma = c(0, 0, 1.1, 0))
plot(fm1)
fm2 <- aov(sqrt(count) ~ spray, data = InsectSprays)
summary(fm2)
plot(fm2)
par(opar)