This example presents a scatterplot matrix for the Iris flower dataset, showing pairwise relationships between sepal and petal measurements, colored by species. It highlights how the visualization reveals clusters and correlations across dimensions. The code uses D3 v7 to create SVG circles, with `scaleLinear` for axes, `scaleOrdinal` for categorical colors, and `axisLeft`/`axisBottom` for ticks. Data is loaded from a CSV via `d3.text`, and mouseover events add a yellow highlight to all circles in a cell, emphasizing points under inspection.