Circles on a Map
This map visualization displays global population by country using semi-transparent circles sized proportionally to 2018 population data from the UN, with a square-root scale for area encoding. The code uses d3.geoNaturalEarth1 projection, d3.geoPath, and d3.geoCentroid to position circles at country centroids, while d3.zoom enables panning and zooming. Hovering reveals country names and population values via SVG title elements, and a custom size legend explains the circle scaling. Data sources include UN population CSV and TopoJSON world atlas geometry.
AI-generated descriptionVisualizing population by country using circles on a map! The area of each circle corresponds to the population of the country it represents. You can also pan & zoom, and hover over each country for more information.