A bifurcation diagram illustrates how the fixed points in a first-order dynamical system evolve as a function parameter changes. Take any vertical line upwards (along the dimension) and note the fixed points at the color boundaries. From brown to purple is a stable point; from purple to brown is an unstable point. The default situation in this example shows a subcritical pitchfork bifurcation. A non-symmetrical perturbation , added with the slider control, changes the system behavior and its bifurcation diagram.