Line Chart with Multiple Lines
This interactive line chart displays one week of temperature readings in Celsius for multiple global cities, sourced from Data Canvas - Sense Your City. The visualization uses `d3.line` with `curveBasis` to create smooth paths, `d3.scaleTime` and `d3.scaleLinear` for axes, and `d3.scaleOrdinal` with `schemeCategory10` for color assignment. A custom `colorLegend` module renders the city key, while data parsing and nesting rely on `d3.csv` and `d3.nest` to group readings by city. The SVG output includes grid lines, axis labels, and a title.