This example visualizes the classic Iris dataset as a scatterplot, mapping sepal length and width to the x- and y-axes. Each data point is rendered as a distinct SVG symbol—circle, cross, or diamond—based on the flower’s species, with color further distinguishing the three classes. The code uses d3.scaleLinear for axes, d3.scaleOrdinal for color and symbol assignment, and d3.symbol with the d3.symbols array to generate the mark paths. A legend maps species to both symbol type and color, while petal length is encoded by a square-root size scale.