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 different symbol shapes representing species. The visualization also includes a custom shape legend identifying each species. The code uses d3.csvParse and d3.fetch to load a CSV dataset, then d3.scaleLinear for axes and d3.scaleOrdinal with d3.symbolsFill to assign distinct geometric markers. Axes are rendered via the d3.axisLeft and d3.axisBottom APIs, while a custom legend module draws symbols and text ticks.