{"version":"1.0","type":"rich","title":"D3 Course 14: Melting Data for Multiple Lines","description":"This line chart visualizes population trends across global regions from 1950 to 2100. It combines data from two UN population CSV files, melting columns into rows and filtering to display only regional aggregates. The chart uses D3 v5 APIs including `scaleTime`, `scaleLinear`, `nest`, and `curveBasis` for smooth lines. A black vertical marker indicates the currently selected year, which updates interactively on mouse movement via the `mouse(this)` function.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/bd2bc1e4e18a45e98c1ae25a7ae56056?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}