Introduction

The XpressProblem class provides a convenient and efficient interface for stating and working with optimization problems. Using this class, optimization problems can be built easily and all features of the Xpress Solver can be accessed.

The classes for modeling problems are spread across several namespaces. The base namespace for everything related to the Xpress Solver in this API is xpress. The sub-namespaces are listed below. See the reference documentation for more details.

xpress::objects

Contains all the classes required for modeling using objects rather than row and column indices. This defines classes like Variable, Expression and XpressProblem that allow convenient and efficient building of problems. This is the main package you will interact with when creating optimization problems.

xpress::maps

Contains implementations of multi-dimensional maps. These maps build on maps provided by the language itself but also provide some more convenient ways to access data. For example, in order to query an element, you do not need to chain several calls to get but can instead put the arguments for all dimensions into a single call.

The XpressProblem class itself is located in xpress::objects. Its fully qualified name is xpress::objects::XpressProblem.

To avoid typing the fully qualified name you can do this:

// Import a whole namespace:
using namespace xpress::objects;
// make sum() function available without qualification:
using xpress::objects::utils::sum;

In the following sections we do not list the required using statements that are required to make functions/classes/interfaces available without full qualification. We assume that appropriate statements have been written at the beginning of the code.