δ F ω dt
Use mouse wheel to zoom animation (canvas is matched to the browser window). α determines point brightness. Dynamics of N = 1 048 576 independent points is plotted. Press Stop button to investigate strange attractor. For small force F or big damping δ values you will get simple regular attractors.

GPU based simulation of the Duffing oscillator. Equations of the particle motion are
    x' = v,
    v' = -δv - x - x3 + F sin(ωt).

The script uses the 4-th order Runge-Kutta integration algorithm.

Simulations on GPU
updated 28 Aug 2013