This example demonstrates a dynamic visualization of a set of circles whose positions and radii oscillate over time, creating a flowing, wave-like pattern. The animation updates every frame at 60 frames per second, with the number of circles varying between 5 and 15. It uses the D3.js library (version 6.6.2) and its `select`, `range`, and `.join` APIs to efficiently bind and update SVG circle elements. The data is procedurally generated using a sine function, and the rendering is handled via SVG with animated attribute changes.