This example displays a scatter plot of the Iris dataset, plotting sepal length against petal length. Points are colored and shaped according to species, with a custom legend identifying each species by its unique symbol. The visualization uses D3.js (v7) to fetch and parse the CSV data from a GitHub repository, then renders the plot within an SVG. It constructs axis scales with `scaleLinear`, applies shape encodings through `scaleOrdinal` and `symbolsFill`, and generates marks via `symbolGenerator`, with axes and legends created by custom functions.