From Chen Ding: Aggregation by Country using Excel + Dropdowns!
This example visualizes the number of video views for Harvardx/MITx online courses in 2013, with circles sized proportionally to view counts and positioned by geographic coordinates on a world map. A dropdown menu filters the view by specific course, and hovering over a circle reveals the country and total views. The map uses a Mercator projection via D3’s `geoMercator` and `geoPath` for landmasses and graticules, while `scaleSqrt` determines circle sizes. Data is loaded as CSV and TopoJSON, with the view rendered as React-driven SVG elements.
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.