This example visualizes the Iris dataset as a scatter plot, encoding petal width and sepal length on the x- and y-axes. Different species are distinguished using D3 symbols (circles, crosses, and diamonds) with red, green, and blue fills. The code builds the chart with a reusable `scatterPlot` function that leverages d3.scaleLinear, d3.scaleOrdinal, d3.symbol, and d3.axisLeft/axisBottom. A legend shows each species with its corresponding symbol and color. The SVG rendering and margins are configured in the main script.