This webpage uses the
Runge-Kutta-Fehlberg fourth-order method with fifth-order error checking (RKF45) to approximate the solution to the problem of the Duffing oscillator:
x¨+δx˙+αx+βx3=γcos(ωt) Below you can specify these various parameters, as well as the initial conditions and starting and end times. The default values give chaotic behaviour.