This example demonstrates animated data binding with D3 selections. A set of circles continuously updates as new data points are generated, with positions, radii, and colors shifting over time. The visualization uses `d3.select` to create an SVG, then the custom `vizData` function applies the data join pattern with `selection.join()`, merging enter and update elements. Data is generated procedurally via `makeData`, producing 15 to 25 circles each frame. The animation runs on a `setInterval` loop at 60 frames per second, with each frame updating the circle attributes directly.