Monthly Archives: August 2016

Map Club, Session 05 — Geographic Projections in D3.js


In its fifth and final summer session, Map Club delved into the geographic projection capabilities of D3.js, a JavaScript library for manipulating documents based on data. D3 supports a comprehensive range of both common and unusual projections, further augmented by the most recent 4.0 release. Attendees sought to become familiar with the syntax for rendering JSON data in the browser, to add interactivity and data-driven attributes to different geographic regions, and to explore some of the less common projections offered by the library.

Tricia used the Albers Equal-Area Conic projection to render outlines of U.S. states and counties, while Emily aligned Gnomonic, Orthographic, and Stereographic projections in an interactive sphere:



Paul Ronga created an impressive interactive map visualizing Swiss census data (view the full version here):


For this session’s resources and materials, visit the Map Club Github repository. And that’s a wrap! Thanks for a great summer series, everyone!

Map Club, Session 04 — Vibrant Maps with Mapzen


Map Club spent this week’s session exploring Mapzen, an open, sustainable, and accessible mapping platform. Attendees focused specifically on Tangram, an open-source renderer that allows intricate control over the design of web-based interactive maps. Mapzen leverages vector graphics and OpenGL to generate speedy, beautifully-rendered tiles, easily displayed using Leaflet.

Centered on Columbia, Tricia customized Tangram’s lighting model to produce a concentrated spotlight:


Jeremiah made use of different point light properties to generate a vivid cityscape:


Along with lighting capabilities and color customization, Tangram allows for custom GLSL. (Full overview here.) Emily used a fragment shader to animate the colors of New York City buildings and water:


Eric imported Transit App trip requests, and used the date of a request to extrude elevation:


A successful week full of beautiful and strange results. Next Tuesday, in our final summer session, we will explore different projections in the D3.js JavaScript library. See you then!

For this session’s resources and materials, visit the Map Club Github repository.