Sophie's version: Aggregation by Country using Excel
This example visualizes the total video views for HarvardX and MITx online courses in 2013, aggregated by country and shown as circles on a world map. Circle size encodes view count, and hovering reveals the country and number of views. The map uses a Mercator projection built with D3’s `geoMercator`, `geoPath`, and `geoGraticule`, layered with land and interior boundaries from the World Atlas TopoJSON. Data is loaded from a remote CSV via D3’s `csv` function, and the circles are positioned using the projection, with their radius scaled by `scaleSqrt` in SVG.
AI-generated descriptionThis is a visualization of the Harvardx/MITx Course-Person Dataset for the academic year 2013. The data shows the number of video views of the online courses, represented by the circles on the map. The data can be found here.
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The world map behind the points is a Mercator type map using the World Atlas TopoJSON. The points are off by a small fraction (down and to the left) however it fits much better on the Mercator projection over the Natural Earth projection. When the user hovers over each point, they can see the latitude and logitude of that deployment.