In the 3D graphic, time runs vertically upwards. In this 2D picture, we ignore the time variable and display each time-dependent trajectory as a curve in the x-y-plane, using one color per trajectory. This makes it easy to follow a single trajectory visually and especially easy to identify periodic trajectories. Another possibility would be to color the trajectories according to time. This would more easily allow to visually grasp the state of the system at a given instant of time. Click the image to return to the 3D version of this data.