{"version":"1.0","type":"rich","title":"Untitled","description":"A choropleth map of population density by census block group uses a sequential color scale from the d3-scale-chromatic library to shade geographic regions. The visualization renders as SVG via d3.geoPath, with a threshold scale mapping density values to the OrRd color scheme and a legend using d3.axisBottom. It loads TopoJSON data containing block group polygons, fills each path according to its population per square mile, and outlines counties with a subtle stroke. The code applies d3.scaleThreshold and d3.scaleSqrt to encode the data range.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/a689b3c19b374aba97bf095b521b2206?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}