Circles on a Map
This visualization displays population by country using proportional circles on a natural Earth projection map, with circle area corresponding to each nation's 2018 population. Users can pan and zoom the map via d3.zoom and hover over countries to reveal population details in a tooltip. The code uses d3.geoPath, d3.geoCentroid, and d3.scaleSqrt to position and size circles, while a custom size legend and color legend are built with D3 selections. Population data originates from a CSV file, joined with TopoJSON world geometry using topojson.feature.
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.