This example visualizes the adjacency relationships in a network as a matrix, where rows and columns correspond to nodes and colored cells indicate the presence of a link. The code uses D3.js v6 to load CSV data from a GitHub gist, constructs a square grid of rectangles sized 17x17 pixels, and encodes edge weights via fill opacity. Interactive mouseover events highlight the entire row and column of a hovered cell and display a tooltip with the link ID. Node labels are rendered as text along both axes.