Line Chart with Multiple Lines
This line chart displays one week of temperature data in degrees Celsius for cities worldwide, sourced from Data Canvas - Sense Your City. The visualization uses multiple lines to compare temperature trends across cities, with each line color-coded by city name. Built with D3 version 5, the code employs `d3.scaleTime`, `d3.scaleLinear`, and `d3.scaleOrdinal` for scaling, `d3.line` with `d3.curveBasis` for path generation, and `d3.nest` for grouping data. A custom color legend component (`colorLegend.js`) renders the categorical color scale, while axes are drawn using `d3.axisLeft` and `d3.axisBottom` with gridlines.