Computing: Free Pascal Programming

3-species predator-prey simulation.

Download LotkaVolterra2 desktop application (Windows 64bit) Download LotkaVolterra2 source code (Lazarus/Free Pascal)

Description: Biology simulation, using an extension of the Lotka-Volterra model, showing the growth of 3 species of a linear food chain: a lowest-level species (ex: mouse) is preyed upon by a mid-level species (ex: snake), itself preyed upon by a top-level species (ex: owl). Simulation data is entered in the main window, sample model parameters, describing 10 common cases, may be loaded from file, via the application menu. Use Start to start the simulation: the number of the 3 species pictures will increase/decrease as time passes. Default simulation time interval is 1 year growth time corresponding to 1 second real time. An entry in the Settings menu allows to run the simulation faster or slower.
This visual part of the simulation is more programming fun of myself than really scientifically useful. If you are seriously interested in the simulation results, use the Graph button to display the variation of the 3 species populations vs. time.
Help concerning the Lotka-Volterra model and its extension to 3 species, as well as help concerning the usage of the application included.

Free Pascal features: Creating images and loading pictures during runtime. Using a timer and the Left, Top and Visible properties of images to create simple simulation programs. Using bitmap canvas to draw mathematical graphs. Reading .INI files.


3-species predator-prey PC application: Simulation window
3-species predator-prey PC application: Graph window