This scatter plot visualizes the Iris dataset, mapping petal length on the x-axis and sepal length on the y-axis. It uses d3.scaleLinear for both axes and d3.extent to compute their domains from the data. Circles are rendered in an SVG via d3.selectAll and the join pattern. The dataset is loaded as CSV with d3.csv from a remote gist URL, and the plot fills the entire browser window.