This example displays Fisher’s iris dataset as a scatter plot of sepal versus petal length, encoding species with different filled shapes. It builds on D3 v7 APIs—d3.scaleOrdinal, d3.symbolsFill, d3.symbol, and axis functions—to generate custom SVG paths for each mark and a dedicated shape legend. A reusable axes module applies left and bottom scales with labeled axes. Data is loaded as CSV from a GitHub repository and parsed with d3.csvParse before being converted to numeric values.