Change size of points in scatter plot

Introduction

Once we have created a basic scatterplot we can change the size of the points based on the size attribute of aes(…) function. An aesthetic or aes(…) is a visual property of the objects in your plot. Aesthetics include things like the size, the shape, or the color of your points.

We can change the size based on categorical variable in our data. We can also change the size of the points explicitly without using categorical variable. We will explore both in the below section.

Procedure

We will be working with MPG data set present in-built in ggplot2. Few of the rows of the dataset are as follows:

We will create scatter plot of displ vs hwy and the size of the points will be based on categorical variable class. We will also create same scatterplot but manually setting the size.

Code

Change size of scatter plot point based on categorical variable:

 
library(ggplot2)
ggplot(data = mpg) + geom_point(mapping = aes(x = displ, y = hwy, size = class))

And the output of above code is:

Change size of scatter plot manually:

 
library(ggplot2)
ggplot(data = mpg) + geom_point(mapping = aes(x = displ, y = hwy), size = 10.0)

And the output of above code is:

Conclusion

Thus we have successfully changed the size of point in scatter plot.

References

• https://stackoverflow.com/questions/34638902/point-size-in-ggplot-2-0-0