An overview of

The FICO^® Xpress BCL Builder Component Library provides an environment in which the Xpress user may readily formulate and solve linear, mixed integer and quadratic programming models. Using BCL's extensive collection of functions, complicated models may be swiftly and simply constructed, preparing problems for optimization. Not merely limited to specific model construction, however, BCL's flexibility makes it the ideal engine for embedding in custom applications for the construction of generic modeling software. In combination with the FICO^® Xpress Optimizer, the two form a powerful combination.

Model formulation using Xpress BCL is constraint-oriented. Such constraints may be built up either coefficient-wise, incrementally adding linear or quadratic terms until the constraint is complete, or through use of arrays of variables, constructing the constraint through a scalar product of variable and coefficient arrays. The former method allows for easier modification of models once constructed, whilst the latter enables swifter construction of new constraints.

BCL supports the full range of variable types available to users of the Xpress Optimizer: continuous, semi-continuous, binary, semi-continuous integer, general and partial integer variables, as well as Special Ordered Sets of types 1 and 2 (SOS1 and SOS2). With additional functions for specifying directives to aid the global search, BCL enables preparation of every aspect of complicated (mixed) integer programming problems.

To complement the model construction routines, BCL supports a number of functions which allow a completed model to be passed directly to the Xpress Optimizer, solved by the optimizer, and solution information reported back directly from BCL. For situations where the BCL solution functions do not provide enough capability to handle a particular user's requirements, problems may be manipulated using the Xpress Optimizer library functions. Such close interactivity between BCL and the Xpress Optimizer make these two libraries a perfect partnership.

BCL also supports a number of functions allowing easy input and output of model and solution data. In addition to a set of useful print functions, other functions also enable the export of constructed models as matrix files in a number of industry standard formats.