{"version":"1.0","type":"rich","title":"heatmap with legend d3","description":"This heatmap visualizes the average fuel economy (mpg) of cars across model years and engine displacement ranges, using color intensity to represent efficiency values. The chart is built with D3 v7, loading CSV data and using `d3.rollup` to aggregate means, `scaleBand` and `scaleTime` for axes, and a sequential color scale with `d3.interpolateBlues`. Interactive tooltips display details on hover, while the legend is generated using the d3-legend library.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/55cb3aee8ed84a70b274c4a36c2f6e7f?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}