Friday, May 26, 2006

Repast Model of the week: GeoSim

International Conflict Research (ICR) group at the Centre for Comparative and International Studies (CIS) Zurich, has numerous Repast models which can be downloaded. Click here to see the models available and for further details. These models use a whole host of Repasts functionality and spaced (from networks to grids).

One model is GeoSim (see Cederman 2003 for more information). GeoSim represents an agent based computational model of an inter-state or world system where sovereign countries (nation-states) are composed of capitals and provinces and interactions determine the rise and fall of territorial agents. The ICR provides a simplified version of the model which can be downloaded.

Further Information

The original source code of the GeoSim model can be found by clicking here.

For further information on the context of GeoSim see: Cederman L-E 2003 "Modelling the size of wars: from billiard balls to sand piles", American Political Science Review, 97(1), 135-150. A copy of the article can be found by clicking here.

To run the model as an executable click here (Sorry it will only work in Windows). For instructions on how to run a Repast model see the Repast website.

Thursday, May 11, 2006


I have just discovered a java library called Trove, which allows you to plug in their versions (eg THashMap) of certain containers (java.util.HashMap, java.util.HashSet, java.util.LinkedList), and use them just like you would with the standard versions gaining performance. For example the THashMap class is a faster than java.util.HashMap. Trove also comes when you download Repast.