{"version":"1.0","type":"rich","title":"d3 Choropleth map","description":"This choropleth map shows U.S. counties colored by their 2023 population estimates, using a logarithmic threshold color scale with seven blues to reveal regional population patterns. It loads population data from a CSV and county boundaries from a TopoJSON file via Promise.all, then renders the map using d3.geoPath on SVG paths. The fill color is assigned per county using d3.scaleThreshold and FIPS codes, with a d3.legendColor legend and a title clarifying the data shown.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/2840cfcad8284166ac3b300746bbad43?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}