How to use the Lotka-Volterra with Harvest Tool

Setting Initial Conditions

The initial conditions for the active trajectory are displayed to the right of the HP graphing plane.

They are set using either the mouse or the keyboard:

• Click the mouse on the HP graphing plane to set H(0) and P(0).
• Click the mouse on the value for one of the initial conditions displayed beside the HP graph to activate a keyboard editor. Set a new number using the number keys, the right and left arrow keys, and the [Delete] key. Press the [Return] key or click the mouse outside the number to leave the editor, set the initial value, and start the trajectory.

  Parameter Sliders

  • Use the sliders to set the values of the growth rate a, the predation rate b, the predator mortality rate c, and the food conversion rate d, the harvest rate for herbivores h_H, and the harvest rate for predators h_P.
  • Press the mouse down on the slider knob for the parameter you want to change and drag the mouse back and forth, or click the mouse in the slider channel at the desired value for the parameter.

  Buttons

  • [Clear] removes all output from the graphs.
  • [Pause] stops a trajectory without canceling it.
  • [Continue] resumes the motion of the paused trajectory.