2D Phase Portrait & Nullclines

Vector fields, nullclines, and trajectories — click to launch orbits

System

Van der Pol
Lotka-Volterra
Duffing
Pendulum
Hopf

Parameters

dx/dt = μ(x−x³/3−y)
dy/dt = x/μ
Click the canvas to start a trajectory. Green = x-nullclines (dx/dt=0), Blue = y-nullclines (dy/dt=0). Fixed points at intersections.