This example shows a scatter plot of iris flower measurements, mapping sepal length to the x-axis and petal length to the y-axis. Each point’s shape encodes the species, with a custom legend explaining the shape-to-species mapping. The visualization loads CSV data from a remote URL, parses it with `d3.csvParse`, and renders marks using `d3.symbol` with the `symbolsFill` scale. Axes are generated via `d3.axisLeft` and `d3.axisBottom`, while the chart updates responsively to the window size.