This example visualizes the classic Iris dataset as a scatter plot, showing petal length against sepal length. Points are colored by iris species according to a categorical scale, with a bespoke color legend positioned in the lower-right corner. The implementation uses D3.js APIs including `scaleLinear`, `scaleOrdinal`, `schemeCategory10`, and `selection.join` to build the chart and its axes declaratively. The code reads CSV data directly and constructs the visualization with the `scatterPlot` module.