Fork of Multiple Line plot with Dropdown
This visualization displays monthly average air quality measurements for London, comparing PM2.5 and PM10 particulate levels across different years from 2010 to 2018. A dropdown menu lets users switch which pollutant is plotted on the y-axis, with each year rendered as a separate colored line using a time-based x-axis. Built with D3 v5, the code uses `scaleTime` and `scaleLinear` for axes, `nest` for grouping data by year, and `transition().duration(1500)` for animated line updates. The data comes from the Kings College London Air Quality Dataset in the London Datastore.