R Statistics Cookbook

How to do it...

We will work with the PlantGrowth dataset, which is already included in R. It contains the weights of certain plants and a variable flagging whether the plant is in the control, treatment1, or treatment2 groups.

1. First, we load the robust package and the dataset:

library(robust)  r = PlantGrowth 

2. Let's model this using standard ANOVA. Because there are no obvious outliers, the standard ANOVA table should match the robust one reasonably well:

d = aov(weight ~ group,data=r ) summary(d) 

The following screenshot shows the classical ANOVA table for the standard model:

Then, type the following code:

plot(d, 2) 

The following ...