This example visualizes the Iris dataset by plotting sepal length against petal length, with each of the three iris species distinguished by a different symbol shape. The scatter plot uses D3 v7’s `scaleLinear`, `scaleOrdinal`, and `symbol` APIs to position points and generate the distinct marker shapes, while a custom shape legend explains the species mapping. The chart is built with reusable D3 modules for scatter plot rendering, axes, and legend, and it loads data via `fetch` and `csvParse` from a raw GitHub CSV file.