EASY-OPT Express

Version 2.0 (2011)

Interactive software system for nonlinear programming

We proceed from the mathematical optimization problem, to minimize a nonlinear objective function f(x,y) subject to nonlinear equality and inequality constraints g1(x,y),..,gm(x,y) and continuous (x), integer or boolean (y) variables. Moreover, there are lower and upper bounds for the variables:

                           min  f(x,y)
            x ε  Rc : gj(x,y)  =  0  ,  j = 1,...me
            x ε  Zi   gj(x,y)  ≥  0  ,  j = me+1,...,m
                           xl  ≤ x ≤ xu  ,  yl  ≤ y ≤ yu

For example, the objective function can be the weight of a mechanical structure that is to be minimized subject to sizing and shape variables, and that the constraints impose limitations on structural response quantities, e.g., upper bounds for stresses or displacements under static loads. We assume that f(x,y) and g1(x,y), ... ,gm(x,y) are continuously differentiable subject to x.
EASY-OPT Express is an interactive user interface running under MS-Windows XP or later, to facilitate the formulation of nonlinear programming problems, their implementation and numerical solution. It is possible to minimize nonlinear functions subject to any nonlinear equality or inequality constraints.

For parameter estimation or data fitting, respectively, see
EASY-FIT Express or EASY-FIT ModelDesign .





Articles and Resources


            arbitrary objective functions depending on optimization variables
            continuous, integer, or boolean variables
            additional nonlinear equality or inequality constraints
            large number of standard test examples
            modeling language for nonlinear functions
    numerical routines
            SQP code NLPQLP for continuou optimization                   
            extended SQP code MISQP for mixed-integer optimization
            automatic differentiation subject to continuous variables
            extremely fast
   user interface
            convenient and flexible modeling language
            'find' and 'filter' commands
            reports and optimization history plots (Gnuplot)
            200 variables
            1,000 constraints
     modeling language (PCOMP)
            highly flexible statements depending on optimization variables
            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, run-time version included
            database with 384 examples
            Windows XP or later

... for more information see the documentation, see easy_opt.pdf



To download EASY-OPTExpress, 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


Articles and Resources:

    continuous test examples: the Hock-Schittkowski collection, the second collection
    mixed-integer test examples: the MINLP collection
    many more publications

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