This example visualizes the distribution of petal lengths across three Iris species using a stacked bar chart with tooltips. The code loads data from a local CSV file and renders the chart as SVG using D3 v7. It employs `d3.stack()` to create stacked segments, `d3.scaleBand()` for the categorical species axis, and `d3.scaleLinear()` for the continuous petal length axis. Interactive mouseover events display tooltips showing the exact petal length for each species and segment.