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)
## Loading required package: acs
## 
## Attaching package: 'acs'
## The following object is masked from 'package:base':
## 
##     apply
    ?df_pop_state
    data(df_pop_state)

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

plot of chunk unnamed-chunk-1

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.