Plotting on the sphere in R

To begin with a caveat, most data I generally prefer not to view on a sphere, including much geographical information. It’s confusing, and half of the surface is completely obscured from view (though I’m more concerned about the half that’s not!). Of course, it really depends on what one is trying to accomplish or convey. End caveat. Below I have provided some example graphics of plotting on spherical surfaces in R. Earth is not spherical, but close enough, and our globe makes for a more interesting illustration.

01

Data in the map surface come from the rworldmap package. I used rworldxtra for convenient access to a higher resolution map layer on which the choropleth polygon colors are assigned. The plots below are a standard terrain image, and a bathymetry data matrix from NOAA, accessed via the marmap package. I added noticeable overlays of major river systems on the last globe using the river data in the mapdata package.

02

03

04

Later I will share some plots where data is added to the 3D surface. Technically the choropleth plot shows aerial-type spatial statistics, in the form of country polygons, which could have been plotted on top of one of the other maps, but I am referring to the addition of lines, points, text, things often added secondarily in all our typical flat plots.

This entry was posted by Matt Leonawicz.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: