In simple regression, we try to determine whether there is a relationship between two variables. It is assumed that there is a high degree of correlation between the two variables chosen for use in regression.

For this section, we will be using the iris dataset. The iris dataset has observations of the different characteristics of iris plants. For regression, we are seeing if there is a relationship between one characteristic of iris plants and others. As mentioned, the characteristics tested will have a high degree of correlation. The iris dataset is as follows:

> data <- read.csv("http://archive.ics.uci.edu/ml/machine-learning-databases/iris/iris.data")

Let's also...