This example pairs a force-directed graph with an adjacency matrix to explore node-link diagrams and network connectivity. The graph uses D3’s `d3.forceSimulation` and `d3.forceLink` to position nodes, while the matrix encodes edge weights as cell opacity. Clicking a node or matrix cell highlights the corresponding row, column, and connected links. The code also enables drag interactions via `d3.drag` and zooming with `d3.zoom`, rendering everything as SVG.