Easy-Fit

Description

EASY-FITModelDesign is a Windows-based application and callable Fortran subroutines for solving parameter estimation problems. Parameter estimation plays an important role in natural science, engineering and many other disciplines. The key idea is, given measured experimental data, estimate parameters of a mathematical model that describes the experiment.

EASY-FITModelDesign can be used to estimate parameters for several types of models:
  • Explicit model functions
  • Laplace Transforms
  • Steady state systems
  • Ordinary differential equations (ODE)
  • Differential algebraic equations (DAE)
  • One-dimensional, time-dependent partial differential equations (PDE)
  • One-dimensional, partial differential algebraic equations (PDAE)

Features & Benefits

  • Extensive documentation. (378 pages, 554 references)
  • Solution of complex identification problems with minimal implementation efforts
  • Intuitively understandable and flexible modeling language
  • Huge number of test cases to start from
  • Sophisticated and up-to-date numerical routines
  • Sound scientific background
  • New (significance levels) and highly complex (optimum design) statistical tools

User Interface

  • Convenient modeling language with automatic differentiation
  • Alternative Fortran interface
  • Up to 20 fitting criteria and data sets
  • Syntax-highlighting editor
  • Extensive report and graphics facilities, also for Gnuplot
  • Input and output of data by text files or Excel, Word output

General

  • Arbitrary fitting criteria depending on the parameters to be estimated, and the solution of the dynamic system Additional nonlinear equality or inequality constraints
  • Second independent model variable called concentration
  • Switching points with restart of integration, e.g., for changing the model
  • Variable switching times, e.g., for modeling dynamical input functions
  • 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
  • Computation of optimal experimental designs (A-criterion)

Ordinary Differential Equations (ODE)

  • Explicit and implicit solvers
  • Stiff and large ordinary differential equations, band structures
  • Shooting method for unstable ordinary differential equations

Ordinary Differential Algebraic Equations (DAEs)

  • Algebraic equations up to index 3
  • Consistent index-1-initial values evaluated internally

One-Dimensional, Time-Dependent Partial Differential Equations (PDEs)

  • Coupled ordinary differential equations
  • Different integration areas with non-continuous transitions
  • Large number of discretization procedures
  • Upwind formulae and ENO method for hyperbolic equations
  • Boundary conditions in Dirichlet or Neumann form or as implicit algebraic equations

Trial Version

A trial version is available containing all features of EASY-FITModelDesign. The trial version is identical to the full version, but data and model sizes are restricted. The trial version runs under Microsoft Windows Vista or XP and comes with a large number of test examples, many of them based on real-life applications. It comes with the royalty-free run-time version of Microsoft Access 2007.

Download EASY-FITModelDesign Trial version: EASYFIT.ZIP (69.4 MB).

To get a trial version for Windows 2000 or earlier, please contact Prof. Klaus Schittkowski.

Installation Notes

  • If the language settings of your Windows system (Start -> Control Panel -> Regional Options) are different from a Western European language, e.g., Chinese, it might happen that EASY-FITModelDesign stops with an error message. Please change the set up, preferably to US English.
  • To replace an existing version of EASY-FITModelDesign:
  1. Export all problems from the old version which you would like to save, into an auxiliary folder.
  2. It is recommended to save the database file EASY_FIT.MDE and all files problems\*.FUN, problems\*.FOR, respectively.
  3. Remove the old version (Start -> Settings -> Control Panel -> Add or Remove Programs).
  4. Delete the installation folder, e.g., C\:EASYFIT.
  5. Install the new version of EASY-FITModelDesign and start the program.
  6. Import all problems exported according to Step 1 (File -> Import).

Technical Support

Technical support is available from the author of EASY-FITModelDesign, Prof. Klaus Schittkowski through a Rogue Wave Forum dedicated to EASY-FITModelDesign.

For more questions about features, installation or numerical routines, you may also contact Professor Schittkowski at klaus.schittkowski@uni-bayreuth.de.

Pricing and Ordering Information

Single-user licenses are available, with academic and multi-license discounts. For pricing and purchasing information for EASY-FITModelDesign 5.0 please contact easyfit@roguewave.com.

System Requirements

Recommended hardware configuration is at least a Pentium IV processor with 512 MB memory on board and at least 600 MHz. The complete installation requires up to 95 MB on hard disk. EASY-FITModelDesign runs under Windows Vista and earlier.

Examples & Additional Resources

Books & Documentation

Examples

Sample Applications

Related Software

EASY-FITExpress: Interactive software system to estimate parameters for dynamic models consisting of analytical functions. Proceeding from given experimental data, i.e., observation times and measurements, the minimum least squares distances of measured data from a fitting criterion are computed. Confidence intervals and priority levels of the parameters are determined. The software is free.

EASY-OPTExpress: Interactive system running under MS-Windows to facilitate the formulation of nonlinear programming problems, their implementation and numerical solution. It is possible to minimize a general nonlinear objective function subject to nonlinear equality or inequality constraints. The software is free.