TP3 area chart
A small multiples area chart visualizes monthly closing prices for Microsoft, Amazon, and IBM from January 2000 through March 2010, with each symbol’s time series drawn as a filled steelblue region. The D3 v4 code uses `d3.text`, `d3.dsvFormat`, `d3.nest`, `d3.scaleTime`, `d3.scaleLinear`, `d3.curveBasis`, and `d3.axisBottom`/`d3.axisLeft` to parse the CSV, group by symbol, and render the SVG paths. A categorical color legend labels each stock.