Hello, A sinusoidally driven and undisturbed cantilever of an atomic force microscope (AFM) oscillates ideally in a sinusoidal fashion but the motion of the cantilever (time-domain trajectory) can become more complicated when it is disturbed by the inter-atomic forces as the cantilever taps on the sample surface. The cantilever dynamics can be better understood in the phase-plane. An undisturbed cantilever shows elliptical trajectories in the phase-plane around a center. On the other hand, a disturbed cantilever can show nonlinear effects like period-doubling, bifurcation and chaos. I'd like to know what can be said about the phase-plane trajectory in terms of the attractor, basin of attraction or the possibility of chaos as shown in the attachement containing my experimental data? In the beginning the phase-plane trajectories circle around a center and as the signal size increases, these trajectories also grow in size and the center transforms into a set of two centers. Thanks.