NLAlgEx - Algebraic nonlinear equations coded in MATLAB

A set of 86 examples for systems of algebraic nonlinear equations of different complexity and size coded in MATLAB

This MATLAB app provides 86 examples of different complexity and size for systems of algebraic nonlinear equations coded in MATLAB. In particular, it can be used with the NLABench app, available in the MathWorks File Exchange, which allows to test algebraic nonlinear solvers.

The way to use the app is as follows. There is a main class NLAlgEx with 2 static methods:

>> NLAlgEx.getNprobs %returns number of available examples

ans =

86

>> NLAlgEx.get(3) % returns problem number 3

ans =

NLProblem with properties:

fun: @CSTR1

fun_addendum: ''

der: []

x0: [7×1 double]

lb: [7×1 double]

ub: [7×1 double]

sol: {[7×1 double]}

The properties contain:

fun: handle to MATLAB function returning the value at the provided argument

fun_addendum: it is used to identify problems that share same function handle

der: could be empty, otherwise a handle to a function evaluating the Jacobian matrix for fun

x0: initial point to start solver iterations

lb: vector of lower bounds for variables

ub: vector of upper bounds for variables

sol: cell array with possible known solutions within the bounds

The app assumes the availability of the MATLAB Optimization Toolbox