This example visualizes the Iris dataset, mapping sepal length and petal length on the x- and y-axes while distinguishing species by shape. Each data point is a d3 symbol, rendered using `symbolGenerator`, with a shape legend showing the species categories. The code builds the visualization with D3 v7, using `scaleLinear`, `scaleOrdinal`, `axisLeft`, and `axisBottom` from the `d3` module. Data is loaded as CSV from GitHub and parsed with `csvParse`. The scatter plot is drawn in an SVG canvas sized to the window, with axes and labels configured programmatically.