Computing: Free Pascal Programming

Predator-prey simulation.

Download LotkaVolterra1 desktop application (Windows 64bit) Download LotkaVolterra1 source code (Lazarus/Free Pascal)

Description: Biology simulation, showing the growth of 2 species, one of them being the predator, the other being the prey, using the Lotka-Volterra model. The users may choose to use the exponential or the logistic growth model for the prey, as they may choose to use the common formulae, with the predation growth rate, or the alternate formulae, with the predation efficiency rate.
Simulation data is entered in the main window, the model parameters, as used with the simulation of the lynx and hares populations in Canada, may be loaded via the program menu. Use Start to start the simulation: the number of predator and prey pictures will increase/decrease as time passes. Default simulation time interval is 1 year growth time corresponding to 1 second real time.
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 prey and predator populations vs. time.
Help concerning the Lotka-Volterra model, as well as help concerning the usage of the application is included.

Change log:
Version 1.0 (January-July 2019): Original program.
Version 1.1 (October 2019):
    - Optional usage of logistic growth (carrying capacity) for the prey.

Free Pascal features: Showing/hiding/changing controls, depending on actual situation. Creating images 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.


2-species predator-prey PC application: Simulation window
2-species predator-prey PC application: Graph window (logistic prey growth)