This example shows a scatterplot of the Iris flower dataset, mapping petal length on the x-axis and sepal length on the y-axis. It loads CSV data with `d3.csv`, uses `d3.scaleLinear` and `d3.extent` to set scales, and renders circles as SVG marks. Axes are added with `d3.axisLeft` and `d3.axisBottom`. The chart fills the browser window and is built with D3 v7 in a plain HTML page, with no React integration despite the metadata suggesting a fork.