{"version":"1.0","type":"rich","title":"D3 Course 12: Circles on a Map","description":"This example visualizes global population estimates for 2018 as semi-transparent circles projected onto a natural Earth map. It uses d3.geoNaturalEarth1 and d3.geoPath to render countries from TopoJSON, while d3.geoCentroid computes each country’s center for circle placement. The data comes from a UN population CSV, merged by country code, with missing or unmatched values highlighted in red. Circles are sized using d3.scaleSqrt, and interactive zoom is enabled via d3.zoom. A custom legend displays population value ticks.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/ce2f667eb1bb43df82a4601e232e236a?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}