The paper presents a Graphical User Interface (GUI) for nonlinear programming in Matlab. The GUI gives easy access to all features in the NLPLIB TB (NonLinear Programming LIBrary Toolbox); a set of Matlab solvers, test problems, graphical and computational utilities for unconstrained and constrained optimization, quadratic programming, unconstrained and constrained nonlinear least squares, box­bounded global optimization, global mixed­integer nonlinear programming, and exponential sum model fitting.

The GUI also runs the linear programming problems in the linear and discrete optimization toolbox OPERA TB.

Both NLPLIB TB and OPERA TB are part of TOMLAB; an environment in Matlab for research and teaching in optimization.

Presently, NLPLIB TB implements more than 25 solver algorithms, and it is possible to call solvers in the Math Works Optimization Toolbox. MEX­file interfaces are developed for seven Fortran and C solvers, and others are easily added using the same type of interface routines.

There are four ways to solve a problem: by a direct call to the solver routine or a call to a multi­solver driver routine, or interactively, using the Graphical User Interface or a menu system.

The GUI may also be used as a preprocessor to generate Matlab code for stand­alone runs. A large set of standard test problems is implemented in TOMLAB. Furthermore, using MEX­file interfaces, problems in the CUTE test problem data base and problems defined in the AMPL modeling language can be solved.