Package LIM , implementing linear inverse models in R

We present R package LIM (Soetaert and van Oevelen 2009) which is designed for reading and solving linear inverse models (LIM). The model problem is formulated in text files in a way that is natural and comprehensible. LIM then converts this input into the required linear equality and inequality conditions, which can be solved either by least squares or by linear programming techniques. By letting an algorithm formulate the mathematics, it becomes very simple to reformulate the model in case a parameter value changes, or a component is added or removed. Three different types of problems are supported: flow networks, reaction networks and other (operations research) problems. The first two cases are based on mass balances of the components. We give three examples, a food web example, a biogechemical reaction example and a blending example. If you use this package, please cite as: (van Oevelen, van den Meersche, Meysman, Soetaert, Middelburg, and Vezina 2009).