The causal interpretation of quantum theory developed by David Bohm introduced trajectories that are guided by a real phase function from the wavefunction in the polar form. A simple model is used to get chaotic motion; the trajectories undergo a transition from order to chaos depending on the relative phase factors and . The trajectories circle close to the minimum (nodal) points. For example, at the origin the squared wavefunction has a minimum for all : . The graphic shows the squared time-dependent wavefunction, the quantum particles, and the complete paths.