EASY-FIT Express

Version 1.4 (2013)

Interactive software system for parameter estimation and experimental design

Given any experimental data, i.e., observation times and measurements, the minimum distances of measured data from a fitting criterion are computed. Up to two independent model variables, e.g., time and concentration, and linear or nonlinear constraints can be handled. A statistical analysis provides confidence intervals for estimated parameters, correlation and covariance matrix, identification of significance levels for estimated parameters, and optimum experimental design. As a by-product, curve and surface fits are available.

The software runs under MS-Windows (64 bit).

For more complex modeling, e.g., based on ordinary differential, differential algebraic, partial differential or partial differential algebraic equations, see EASY-FIT ModelDesign. For minimizing any nonlinear functions subject to nonlinear constraints, see EASY-OPT Express.





Articles and Resources


            arbitrary fitting criteria depending on parameters to be estimated
            additional nonlinear equality or inequality constraints
            second independent model variable called concentration
    numerical routines
            Gauss-Newton-type SQP methods, various versions
            automatic differentiation
            alternative norms (sum of absolute values,  maximum of absolute values)
            confidence intervals for estimated parameters, correlation and covariance matrix
            identification of significance levels for estimated parameters
            extremely fast routines
   user interface
            convenient and flexible modeling language
            'find' and 'filter' commands
            extensive report and graphics facilities, also for Gnuplot
            3D plots for two model or input variables, respectively
            in- and output of data from and to text or Excel files
            30 fitting criteria and data sets
            100 model variables
            2,000 time values
            3,000 experimental data
            200 linear or nonlinear constraints
              - limited by size of internal working arrays
     modeling language (PCOMP)
            highly flexible statements depending on parameters to be estimated
            tabulated data, splines, linear and piecewise constant interpolation
            indexed variables and functions
            (nearly) no limitations for number of lines of code
            numerical routines in Fortran, executable outside of the GUI
            GUI in VBA, Microsoft Access 2007, run-time version included
            database with 240 examples

... for more information see the documentation (378 pages, 554 references) easy_fit.pdf



To download EASY-FIT Express, click here.



For more questions about features, installation, numerical routines, please contact
Prof. Klaus Schittkowski  
Department of Computer Science phone: (+49)921 553278
University of Bayreuth fax: (+49)921 553238
D-95440 Bayreuth, Germany klaus.schittkowski@uni-bayreuth.de

Attach your data fitting model in mathematical formulation to find out whether it can be treated by EASY-FIT Express or not.

Articles and Resources:

    book: Numerical Data Fitting in Dynamical Systems, Kluwer Academic Publishers
    many more publications

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