This example shows a force-directed network graph built from a CSV file of names and connection weights, rendered as circles and lines on an HTML5 Canvas. It uses d3.forceSimulation with forceX, forceY, forceCollide, forceManyBody, and forceLink to position the nodes, updating the canvas on each simulation tick via the `ctx` drawing context. The visualization reads data.csv asynchronously with d3.csv, constructs the node and link arrays, and then starts the simulation, with node radius fixed at 7 pixels.