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