

   InsectSprays {base}                          R Documentation

   EEffffeeccttiivveenneessss ooff IInnsseecctt SSpprraayyss

   DDeessccrriippttiioonn::

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

   UUssaaggee::

        data(InsectSprays)

   FFoorrmmaatt::

        A data frame with 72 observations on 2 variables.

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

   SSoouurrccee::

        Geoffrey Beall, (1942).  ``The Transformation of Data
        from Entomological Field Experiments'', Biometrika,
        pages 243-262.

   RReeffeerreenncceess::

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

   EExxaammpplleess::

        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)

