This example shows a small directed force-directed graph with three linked nodes and four labeled points. The simulation uses d3.forceSimulation with forceManyBody, forceLink, and forceCenter to position the nodes as they repel and connect. The SVG output renders circles and lines that update their coordinates on each tick event. The code uses d3.select and d3.forceSimulation, with the graph data defined inline as an array of nodes and links.