30.01.2015 Views

ILOG CPLEX C++ API 9.0 Reference Manual

ILOG CPLEX C++ API 9.0 Reference Manual

ILOG CPLEX C++ API 9.0 Reference Manual

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Refer to the <strong>ILOG</strong> Concert Technology <strong>Reference</strong> <strong>Manual</strong> for more information about<br />

these classes.<br />

IloCplex Optimizer Options<br />

An instance of the class IloCplex is not really only one algorithm, but, in fact,<br />

consists of a set of highly configurable algorithms, also known as optimizer options.<br />

They include primal and dual simplex algorithms, barrier algorithm, a sifting algorithm,<br />

a network simplex algorithm, and a branch & cut algorithm for MIPs. Though in most<br />

cases IloCplex can be used like a black box, the optimizer options can be selected<br />

individually to provide a wealth of parameters that allow you to fine tune the algorithm<br />

to your particular model. In the case of the mixed integer optimizer, you can use your<br />

own goals or callbacks and directly control the branch & cut search carried out by<br />

IloCplex.<br />

The most general kind of problem is a MIP. You might think of the LPs as a subset of<br />

MIPs: an LP is a problem in which the model is:<br />

◆ without integer variables,<br />

◆ without Boolean variables,<br />

◆ without semi-continuous variables,<br />

◆ without piecewise linear functions,<br />

◆ without a quadratic component in the objective function,<br />

◆ without quadratic constraints,<br />

◆ and without a special ordered set (SOS).<br />

For linear programming problems (LPs), a variety of additional solution information can<br />

be queried. These queries include dual information or, with the appropriate optimizer<br />

option, basis information. Sensitivity analysis allows you to analyze how you can<br />

modify your model while preserving the same solution. Or, if your model is infeasible,<br />

the infeasibility finder enables you to analyze the source of the infeasibility.<br />

<strong>ILOG</strong> <strong>CPLEX</strong> <strong>C++</strong> <strong>API</strong> <strong>9.0</strong> REFERENCE M ANUAL 17

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!