profound knowledge and sharp mind were of great help. Prof. Kurth gave me the opportunity to work at his Chair for Graphics Systems at the Brandenburg Technical University of Cottbus, where part of the implementation for this thesis was done, and he also enabled my switch to the Chair for Computer Graphics and Ecological Informatics at the Georg-August-University of Göttingen in 2008.I also thank Prof. Dr. Robert Schaback for his interest in this topic and taking the position as my secondary supervisor. He gave me advice in numerical things and we also had some fruitful discussions.My gratitude goes to Prof. Dr. Paul-Henry Cournède for inviting me to the École Centrale Paris, where I could present some of my work, with subsequent prolific discussions, and for becoming my third referee.Much appreciation goes to Dr. Ole Kniemeyer, who created the programming language XL and the implementation of GroIMP. Without his prior work the proposed extension to the language would not have been possible.Special thank also goes to my colleagues Prof. Dr. Gerhard Buck-Sorlin, Dr. Jochem B. Evers and Dr. Katarína Smoleňová, who as the main users of the present work were testing the software and provided useful feedback that helped to improve it.Thank also goes to people that helped to improve the GroIMP software, especially (in alphabetical order) Octave