R: Data Analysis and Visualization

Adding linear model lines

In this recipe, we will learn how to fit a linear model and plot the linear regression line on a scatter plot.

Getting ready

All you need for the next recipe is to type it at the R prompt as we will only use some base functions. You can also save the recipe code as a script so that you can use it again later on.

How to do it...

Once again, let's use the mtcars dataset and draw a linear fit line for mpg versus disp:

plot(mtcars$mpg~mtcars$disp)
lmfit<-lm(mtcars$mpg~mtcars$disp)
abline(lmfit)

How it works...

We first draw the basic scatter plot of mpg versus disp. Then, we fit a linear model to the data using the lm() function, ...