Monday 16 February 2015

Simulation of a branching process

Here is something for Lecture 14 (on branching processes).

Readme first. You can run this demo in your browser, but you will need to install the Wolfram CDF player. It may take a few moments to load, so please be patient. Also, there seems to a problem at present with the plugin running in Chrome, so you might have to use a different browser. The best thing is to download the demo from the link on the page ("Download Demonstration as CDF") and then run the demo in Mathematica on your own computer. Here is a screenshot from the demo.

This Demonstration shows up to six simulated generations of a branching process. The distribution of the number of descendants of each member of the population can have either a Bernoulli, Poisson, or geometric distribution; the parameters of these distributions can be set with sliders. From the three figures, the left one shows the simulated branching process, the upper-right one shows the probability of ultimate extinction as a function of a parameter of the distribution, and the lower-right one shows the probabilities of the size of the population at the selected generation.

To run the demo click on Simulating the Branching Process
[from the Wolfram Demonstrations Project by Heikki Ruskeepää]