Line Chart with Multiple Lines
This line chart displays one week of temperature readings in degrees Celsius for cities worldwide, with each city represented by a colored line. The chart uses D3 v5’s `scaleTime`, `scaleLinear`, and `nest` to group data by city, while `axisBottom` and `axisLeft` render the labeled axes with grid lines. A `colorLegend` function, built with SVG circles and text, maps city names to a `schemeCategory10` palette. The data originates from Data Canvas - Sense Your City, and the chart emphasizes final temperature values by sorting city lines in descending order.