{"version":"1.0","type":"rich","title":"Choropleth map","description":"A choropleth map shows San Francisco’s 2025 tree-canopy rate by supervisor district, colored on a green sequential scale with a gradient legend and hover tooltips. Built with D3 v7, it uses `d3.geoMercator` and `d3.geoPath` to render GeoJSON district boundaries, while district-level data from a CSV is joined via a `Map`. `d3.scaleSequential` with `interpolateGreens` drives fills, and the vertical legend uses `d3.axisRight` and a linear gradient.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/7dea6c2fbd0946feb82ac012bfd781c4?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}