This example presents a 4×4 scatter plot matrix comparing all numeric fields of the Iris dataset (sepal length/width, petal length/width). Each cell uses colored circles, scaled by d3.scaleLinear and colored by d3.scaleOrdinal with the schemeSet1 palette, to distinguish the three iris species. Data is loaded via d3.csv from a remote gist. Titles appear only on diagonal plots, and axes are rendered with d3.axisLeft and d3.axisBottom, while the SVG matrix is dynamically generated by nested loops.