Exercise

Graduated symbol maps

There are many other effective ways to map statistical data besides choropleth maps. One such example is the graduated symbol map, which represents statistical variation by differently-sized symbols. In this exercise, you'll learn how to use the st_centroid() tool in the sf package to create points at the center of each state to be used as inputs to a graduated symbol map in ggplot2.

Instructions

100 XP

Use the st_centroid() function to generate point centers for each US state.
When plotting the centers, set the size parameter to estimate to scale the point sizes.
Use the scale_size_continuous() function to adjust the range of sizes on the map.