This example visualizes a chord diagram showing relationships between four groups, with ribbon thickness representing the magnitude of connections between them. The code uses `d3.chord()` to compute group and link data from a hardcoded 4x4 matrix, then renders the outer arcs with `d3.arc()` and the connecting ribbons with `d3.ribbon()`. Each arc and ribbon is colored based on its source group using a predefined color array. The SVG is appended to a div, centered within a 440x440 viewport, with stroke outlines on all paths for clarity.