Open and Plot Shapefiles in R



Shapefiles, a popular format for storing geospatial information, are easily handled in R using the sf package. This guide will demonstrate how to read shapefiles into R and visualize them using either base R or the ggplot2 package.

Background map section About Maps

About shapefiles


If you did not find the geospatial data you need in existing R packages (see the map section), you need to find this information elsewhere on the web.

Usually, you will find it as a shape file format. This format is composed by several files that you need to keep together in the same folder.

Find and download a shapefile.


You need to dig the internet to find the shape file you are interested in. For instance, this URL will redirect you to a zipped shape file containing the world boundaries.

You can download it and unzip it with R:

# Download the shapefile. (note that I store it in a folder called DATA. You have to change that if needed.)
download.file("http://thematicmapping.org/downloads/TM_WORLD_BORDERS_SIMPL-0.3.zip", destfile = "DATA/world_shape_file.zip")
# You now have it in your current working directory, have a look!

# Unzip this file. You can do it with R (as below), or clicking on the object you downloaded.
unzip("DATA/world_shape_file.zip", junkpaths = FALSE)
#  -- > You now have 4 files. One of these files is a .shp file! (TM_WORLD_BORDERS_SIMPL-0.3.shp)

Read it with sf


The sf package offers the st_read() and the read_sf() functions that allows to read shapefile using the following syntax.

As a result you get a geospatial object (my_sf here) that contains all the information we need for further mapping. Please try the following command to understand how this object works:

# Read this shape file with the sf library.
library(sf)
my_sf <- read_sf("TM_WORLD_BORDERS_SIMPL-0.3.shp")

# -- > Now you have a sf object (simple feature data frame). You can start doing maps!

Plot it with base R


The basic plot() function knows how to plot a geospatial object. Thus you just need to pass it my_sf and add a couple of options to customize the output.

# Basic plot of this shape file:
par(mar = c(0, 0, 0, 0))
plot(st_geometry(my_sf), col = "#f2f2f2", bg = "skyblue", lwd = 0.25, border = 0)

Plot it with ggplot2


It is totally possible (and advised) to build the map with ggplot2, using the geom_sf() function as described below.

# Plot it
library(ggplot2)
ggplot(my_sf) +
  geom_sf(fill = "#69b3a2", color = "white") +
  theme_void()

Going further


This post explains how to read and plot a shapefile in R.

You might be interested in how to customize the map (select regions, change colors, etc.) and more generally in the map section.

Related chart types


Map
Choropleth
Hexbin map
Cartogram
Connection
Bubble map



❤️ 10 best R tricks ❤️

👋 After crafting hundreds of R charts over 12 years, I've distilled my top 10 tips and tricks. Receive them via email! One insight per day for the next 10 days! 🔥