{"version":"1.0","type":"rich","title":"Proportional Symbols Map in D3","description":"A proportional symbols map visualizes transportation cost indices across U.S. states using D3.js and the topojson library. Each state is rendered as a gray polygon with a circular symbol whose size corresponds to its cost value. The visualization employs an Albers equal-area projection via `d3.geoAlbersUsa` and `d3.geoPath`, with state centroids hardcoded to position the proportional circles. Interactive tooltips appear on hover, while symbols animate on load. The map is drawn in SVG with data fetched from a CSV hosted on GitHub.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/8f9ee4fe953c49b9a40307528006306e?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}