title: Dynamical modeling and multi-experiment fitting with PottersWheel.
abstract: BACKGROUND
  Modelers in Systems Biology need a flexible framework that allows them to easily create new dynamic models, investigate their properties and fit several experimental datasets simultaneously. Multi-experiment-fitting is a powerful approach to estimate parameter values, to check the validity of a given model, and to discriminate competing model hypotheses. It requires high-performance integration of ordinary differential equations and robust optimization.
  
  
  RESULTS
  We here present the comprehensive modeling framework Potters-Wheel (PW) including novel functionalities to satisfy these requirements with strong emphasis on the inverse problem, i.e. data-based modeling of partially observed and noisy systems like signal transduction pathways and metabolic networks. PW is designed as a MATLAB toolbox and includes numerous user interfaces. Deterministic and stochastic optimization routines are combined by fitting in logarithmic parameter space allowing for robust parameter calibration. Model investigation includes statistical tests for model-data-compliance, model discrimination, identifiability analysis and calculation of Hessian- and Monte-Carlo-based parameter confidence limits. A rich application programming interface is available for customization within own MATLAB code. Within an extensive performance analysis, we identified and significantly improved an integrator-optimizer pair which decreases the fitting duration for a realistic benchmark model by a factor over 3000 compared to MATLAB with optimization toolbox.
  
  
  BACKGROUND
  PottersWheel is freely available for academic usage at http://www.PottersWheel.de/. The website contains a detailed documentation and introductory videos. The program has been intensively used since 2005 on Windows, Linux and Macintosh computers and does not require special MATLAB toolboxes.
  
  
  BACKGROUND
  Supplementary data are available at Bioinformatics online.
authors.affiliation: Freiburg Center for Data Analysis and Modeling, Freiburg University, Freiburg, Germany. maiwald@fdm.uni-freiburg.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Maiwald
authors.forename: Jens
authors.initials: J
authors.lastname: Timmer
mesh_terms: D003198:Computer Simulation; D011381:Programming Languages; D015398:Signal Transduction; D012984:Software; D049490:Systems Biology / Q000379:methods*