This example displays a scatter plot of the Iris dataset, mapping petal length and petal width while coloring points by species using a custom marker function. It renders as an SVG via React and D3 v6, using `d3.csv` to load data, `scaleLinear` and `extent` for axes, and `axisLeft`/`axisBottom` for tick marks. The code also appends rotated axis labels and sets circle radii, with point colors assigned per species.