Generate a regression line of data using R

In this example, we use the abline function to portray a regression line of our data.

How to do it...

We can use this script:

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

#Let us also clean up the data so as to be more readable
colnames(data) <- c("sepal_length", "sepal_width", "petal_length", "petal_width", "species")

# call plot first
plot(data$sepal_length, data$petal_length)

# abline adds to the plot
abline(lm(data$petal_length ~ sepal_length), col="red")

It results in a similar Scatter plot but with a regression line included:

How it works...

We are using the same iris dataset as in the previous example.

We have seen how plot can produce a Scatter plot. The addition by abline is to calculate and draw out the regression line on top of the Scatter plot.

The regression does not appear to be a great fit as there are big chunks of data points far away from the line.