Introduction

What is a Choropleth?

A choropleth is a map which

1. Shows geographic boundaries.
2. Colors those regions based on some metric.

Choropleths are useful for visualizing data where geographic boundaries are a natural unit of aggregation. For example, here is a choropleth that shows 2012 US State Population Estimates:

library(choroplethr)
?df_pop_state
data(df_pop_state)

state_choropleth(df_pop_state, title="2012 US State Population Estimates", legend="Population")

What is choroplethr?

choroplethr is an R package that facilitates the creation of choropleth maps in R. It does this in 3 ways.

1. It provides ready-made functions for creating choropleths with four different maps.
2. It provides API connections to interesting data sources for making choropleths.
3. It provides a framework for creating choropleths from arbitrary shapefiles.

The remaining vignettes explain these features in more detail.