R預設的資料集InsectSprays

這個InsectSprays資料集，含有72筆資料，每筆有下面兩個欄位：

• count：蟲子出現的個數
• spray：使用的殺蟲劑，分成A, B, C, D, E, F

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

上面的圖片程式碼來自於InsectSprays資料集的說明，如下：

require(stats)
require(graphics)

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)

_EOF_