This example shows a chord diagram generated from a 3x3 matrix of numeric values, using dark translucent ribbons to visualize connections between three groups. The code builds the visualization with D3 v7, using `d3.chord()` to compute the chord layout with sorted subgroups and angular padding, then renders each chord with `d3.ribbon()` at a fixed radius. The diagram is drawn as SVG paths inside a centered group element, with the input data provided as a static array in the script.