This example visualizes the Iris dataset as a scatter plot with D3.js v6 in React, mapping petal length and width to the x- and y-axes. Each circle’s fill color distinguishes the three species (setosa, versicolor, and virginica) via a custom marker function. The code loads CSV data from a GitHub gist, parses numeric fields, and uses `scaleLinear`, `extent`, `axisLeft`, and `axisBottom` to render axes with SVG. Although `rx` and `ry` attributes are set from sepal dimensions, they have no visual effect on circles.