Two autonomous SVG panels animate circles whose positions and radii shift continuously via a sinusoidal data generator. Each frame, `setInterval` updates data arrays produced by `makeData`, while `vizDraw` uses D3 selections and the `join` method to bind and redraw circles. The upper panel renders black circles on white, the lower white circles on black, driven by sine and cosine functions with a time-stepped parameter. Both SVGs redraw at 60 frames per second.