This example combines a force-directed graph with an adjacency matrix to visualize network data. The code reads a small dataset of nodes and links, rendering the graph as SVG circles and lines using `d3.forceSimulation`, `forceLink`, `forceManyBody`, and `forceCenter`. Users can drag nodes and apply zoom via `d3.zoom`. Clicking a node highlights its corresponding row and column in the adjacency matrix, which is built with D3 selections and `rect` elements. The visualization uses a color scale for node groups and includes a dropdown to order matrix rows.