StellaR: A software to translate Stella models into R open-source environment

Stella is a popular system dynamics modeling tool, which helps to put together conceptual diagrams and converts them into numeric computer models. Although it can be very useful, especially in participatory modeling, it lacks the power and flexibility of a programming language. This paper presents the StellaR software which translates a Stella model into a model in R, an open source high level programming language. This allows using conceptual modeling tools provided in Stella, together with computational functionality and programming flexibility provided in R. It also opens access to powerful software libraries available in R, which is especially useful for spatial modeling. 2012 Elsevier Ltd. All rights reserved. Software availability Name of software: StellaR Developer: Babak Naimi, Alexey Voinov Download: http://www.r-gis.net/stellar Year first available: 2011 Program language: Python Program size: 3.0 MB Availability and cost: Open source The system dynamics simulation approach helps to understand the complex interrelationships existing between different components within a system. Several well-established dynamic simulation systems including Stella, PowerSim, Berkeley Madonna, Vensim, Simile, etc. offer similar features and have been used for modeling studies. Stella was one of the first dynamic modeling systems to achieve broad recognition and use, due to its userfriendly graphic interface. One of the reasons that system dynamics software became so popular in modeling is that they provide handy tools to put together conceptual diagrams, and provide tools to convert them into numeric computer models. Although they can be very useful for specific applications they often lack the full power and flexibility of a programming language (Petzoldt and Rinke, 2007). They are also quite restrictive for spatial dynamics and have limited functionality for model analysis (calibration, statistical analysis, etc.). Besides, they are proprietary and