8.1 Introduction

A satisfying and important aspect of geographic research is communicating the results.Map making — the art of cartography — is an ancient skill that involves communication, intuition, and an element of creativity.Static mapping is straightforward with plot(), as we saw in Section 2.2.3.It is possible to create advanced maps using base R methods (Murrell 2016), but this chapter focuses on dedicated map-making packages.When learning a new skill, it makes sense to gain depth-of-knowledge in one area branching out.Map making is no exception, hence this chapter’s coverage of one package (tmap) in depth rather than many superficially.In addition to being fun and creative, cartography also has important practical applications.A carefully crafted map is vital for effectively communicating the results of your work (Brewer 2015):

Amateur-looking maps can undermine your audience’s ability to understand important information and weaken the presentation of a professional data investigation.

Maps have been used for several thousand years for a wide variety of purposes.Historic examples include maps of buildings and land ownership in the Old Babylonian dynasty more than 3000 years ago and Ptolemy’s world map in his masterpiece Geography nearly 2000 years ago (Talbert 2014).

Map making has historically been an activity undertaken only by, or on behalf of, the elite.This has changed with the emergence of open source mapping software such as the R package tmap and the ‘print composer’ in QGIS which enable anyone to make high-quality maps, enabling ‘citizen science’.Maps are also often the best way to present the findings of geocomputational research in a way that is accessible.Map making is therefore a critical part of geocomputation and its emphasis not only on describing, but also changing the world.

This chapter shows how to make a wide range of maps.The next section covers a range of static maps, including aesthetic considerations, facets and inset maps.Sections 8.3 to 8.5 cover animated and interactive maps (including web maps and mapping applications).Finally, Section 8.6 covers a range of alternative map-making packages including ggplot2 and cartogram.