This interactive scatter plot matrix visualizes the Iris dataset, showing pairwise relationships between four flower measurements—sepal length, sepal width, petal length, and petal width—with points colored by species. Using d3.brush, users can drag across any off-diagonal cell to filter and highlight points across all other cells simultaneously, while diagonal cells display histograms of each variable's distribution. The visualization is built with d3.v4, rendering axes and circles as SVG elements, with scales derived from the CSV data's numeric ranges.