A Simple Guide to Scatterplots in R

Scatterplots can visualize the relationship between two variables.

For example, the relationship between hours studied and exam scores.

Create a Table in R

library(data.table) 

data <- data.table(
  hours_studied = c(2, 5, 3, 6, 4, 7, 5, 8),
  exam_scores = c(65, 75, 70, 85, 80, 90, 75, 95) ) 

print(data) 

In R, the output should look something like this.

   hours_studied exam_scores
1:             2          65
2:             5          75
3:             3          70
4:             6          85
5:             4          80
6:             7          90
7:             5          75
8:             8          95

Basic Plot

Use the plot() function in R to visualize a basic relationship between hours studied and the corresponding exam scores.

plot(x = data$hours_studied, y = data$exam_scores, main = Basic Plot)

Tweaks

Adding some elements all good graphs should have.

1. A Title
2. X and Y labels

plot(data$hours_studied, data$exam_scores, 
     main = "Hours Studied and Exam Scores",  # Title of the plot
     xlab = "Hours Studied",              # Label for the x-axis
     ylab = "Exam Scores",              # Label for the y-axis
     col = "blue",                   # Color of the points
     pch = 16,                       # Shape of the points 
)

That’s It

Easy right?

With four lines of code, we see that more hours spent studying contribute to higher scores on exams.

This guide is just the beginning, you’ll find a ton more guides on how to complicate things further both on Medium and the broader internet.

Refer back to this guide if you ever need a refresher on the basic fundamentals.