Sprott D

Sprott D — one of J. C. Sprott's simple chaotic flows (1994), realized as an analog circuit at glensstuff.com. Found by systematic search for the algebraically simplest systems that still produce chaos.

Five terms, two of them nonlinear (y² and xz). ∇·F = x, which changes sign at x = 0: volume grows where x > 0 and shrinks where x < 0, so the flow is dissipative only on average along the attractor.

dx/dt = −y
dy/dt = x + z
dz/dt = xz + 3y²

Open Sprott D in chaosrack →

It opens running, on the model selector, with its own knobs. Rotate it by dragging, zoom with the wheel, and turn the parameters to see what the figure does when the system changes.