#MUSAMasterClass Featuring Tyler Morgan-Wall: 3D Mapping and Dataviz in R

On November 15, Tyler Morgan-Wall, SAS’09, a researcher for the Institute for Defense Analyses, led a workshop on the rayshader package, an open-source mapping tool he authored to create 2D and 3D data visualizations in the programming language R. The event, sponsored by the Master of Spatial Analytics (MUSA) Program and Penn IUR, was part of the semi-annual MUSA Master Class series, which brings together data scientists worldwide to learn from expert practitioners in data analytics.

Participants joined the workshop at the Weitzman School of Design and through a live webcast. After a brief introduction by MUSA Director Ken Steif, Morgan-Wall explained that rayshader gives users a high degree of control and flexibility in map design, allowing users to create graphics directly from elevation data. Morgan-Wall said the tool improves data scientists’ ability to create realistic hill-shaded elevations, which are critical to a map’s legibility and power to communicate.

Emphasizing the value of compelling graphics, Morgan-Wall argued that, to realize public policy goals, convincing the experts is not enough: the public also needs to understand the data and, for that, clear and cogent visualizations are essential. “Science and policy analysis that engages the public,” he said, “is infinitely more valuable than science and policy analysis that only engages people in your field.”

After reviewing the fundamentals of 3D mapping in rayshader, Morgan-Wall explained how to generate hill shading, demonstrating the use of variables such as time of day, time of year, and geographic context; he noted, also, how the tool detects and illustrates bodies of water. He then showed how the package renders depth over time to allow mapmakers to depict changes in water levels and other dynamic data. 

Morgan-Wall then walked participants through examples of data visualizations. Using Miami Beach as a model, he showed students how to plot climate data and illustrate rising sea levels. Using Philadelphia as a model, he demonstrated how to predict sunlight reduction levels from the hypothetical addition of a skyscraper in the University City neighborhood.

Following his talk and demonstration, Morgan-Wall encouraged participants to replicate his analyses using open-source data he posted on GitHub, an online repository of code that facilitates collaborative software development. Participants’ work can be seen on social media using the hashtag #MUSAMasterClass. If you missed the workshop, you can watch the video (above) and access the code at GitHub.