Comparative Thematic Mapping with Mapdeck

Compare mapping styles like a choropleth, dot density map, proportional symbols map, and 3D choropleth using Indian electricity and latrine access data

shiny
mapdeck
sf
geospatial
Published

March 25, 2019

The app linked below uses the {mapdeck} library to compare common thematic mapping styles using Indian electricity and latrine access data. These styles include a choropleth, a dot density map, a proportional symbols map, and a 3D choropleth.

https://shiny.socialcops.com/thematic_mapping/

You can also find its Github repo.

A brief summary of pros and cons of these thematic maps is below. For a fuller treatment, please see my SocialCops blog post on this topic.

Choropleths

A choropleth gives the simplest view of the spatial distribution of a standardized rate, but conceals the vastly-different underlying population counts.

Choropleth of Indian household electricity access (1991-2011)

Choropleth gif

Dot density maps

A dot density map provides a method to spatially visualize clusters of a raw count, while sacrificing the ability to retrieve numeric data.

Dot density map comparing urban and rural households having access to both electricity and latrines (2011)

Dot density gif

Proportional symbols maps

A proportional symbols map can communicate both a standardized rate and a raw count through the color and size aesthetics, yet congestion is often a dilemma.

Proportional symbols map depicting household latrine access (1991-2011)

Proportional symbols gif

3D choropleths

A 3D choropleth can map a rate and a raw count, while preserving the original geographic shapes, but at the cost of visual clarity.

2011 households having access to neither electricity nor a latrine

3D gif