This example shows a scatter plot of Iris flower measurements, mapping sepal length on the x-axis and petal length on the y-axis, with species distinguished by different symbol shapes. The visualization includes a custom shape legend positioned within the plot. It uses D3 v7’s `scaleLinear` for axes, `scaleOrdinal` with `symbolsFill` for shape encoding, and the `symbol` generator to render marks. Data loads asynchronously from a CSV file via `fetch` and `csvParse`, with axes and legend constructed through reusable functions that accept configurations.