+----------------+-------------------+
| InsectSprays   | R Documentation   |
+----------------+-------------------+

Effectiveness of Insect Sprays
------------------------------

Description
~~~~~~~~~~~

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

Usage
~~~~~

::

    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**, 243â€“262.

References
~~~~~~~~~~

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

Examples
~~~~~~~~

::

    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)

