This example visualizes the Zachary Karate Club dataset as an adjacency matrix, displaying the 34 members and their 78 connections. Each cell represents a potential edge between two nodes, with fill opacity proportional to edge weight. The visualization uses d3.v3’s `d3.svg.axis` for ordinal axes and SVG `rect` elements for matrix cells. Data loading uses `d3.csv` with a `queue()` helper to parse node and edge lists from separate CSV files. Interactive highlighting is implemented through `mouseover` events that emphasize entire rows and columns.