This example shows an interactive scatter plot of the Iris dataset, mapping sepal length to the x-axis and petal length to the y-axis. Points are colored and shaped by species, with a custom legend displaying the categorical shapes. Built with D3 v7, it uses `scaleLinear` for axes, `scaleOrdinal` and `symbolsFill` for shape encoding, and `d3.csvParse` to load data from a remote CSV file. Axes and legend are modularized into reusable functions that render via SVG.