This example visualizes the distribution of petal length across iris species using a stacked area chart. It loads CSV data from a GitHub gist via D3’s `csv` method, then applies `scaleBand` for species categories and `scaleLinear` for petal length values. The chart uses `stack` and `area` generators to render a single filled area, with `axisBottom` and `axisLeft` for axes, and a title annotation. SVG output is produced through D3 selections.