{"version":"1.0","type":"rich","title":"Selecting a Year on Line Chart","description":"A line chart shows population change from 1950 to 2100 across world regions, with a vertical black line marking a user-selected year. Clicking or dragging on the chart updates the line position, and hovering triggers the same interaction. The visualization uses D3 v5 APIs including `scaleTime`, `scaleLinear`, `axisBottom`, `axisLeft`, `line`, `curveBasis`, and `nest`, plus a custom `colorLegend`. Data comes from UN population estimates and medium variant projections, loaded via D3's `csv` function and processed with `melt` to reshape the data into tidy format.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/b708b5269bc345b1b36fb348af989381?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}