{"version":"1.0","type":"rich","title":"Melting Data for Multiple Lines","description":"This example visualizes population over time by region using multiple smoothed lines, with a color legend identifying each region. The data is loaded from UN population estimate CSVs, then transformed using a custom `melt` function that reshapes wide-format data into long format for D3 line generation. The visualization uses `d3.scaleTime`, `d3.scaleLinear`, `d3.nest`, and precomputed curve paths with `d3.line` and `curveBasis`. Axes are rendered with `d3.axisBottom` and `d3.axisLeft`, while a custom legend component manages color-coded circles using `d3.scaleOrdinal` and `schemeCategory10`.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/8199d0f1e82541fe97fcd32fa65173e2?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}