Fourier Sketch

A continuous line can be treated as a complex signal changing over time. A Fourier transform decomposes that signal into circles rotating at different sizes, speeds, and directions. Chain those circles together, and the final point redraws the original line.

Draw one continuous line on the canvas; its endpoint is automatically connected to the start. Reduce the circle count and the fine details disappear first — the same basic idea behind lossy compression. RMSE measures reconstruction error, while energy shows how much of the signal the selected frequencies preserve.