LotSizingDataModel.Solver.Xpress Directory Reference

Files
	XpressAsciiSolutionValueParser.cs
	XpressRuntimeLocator.cs
	XpressSolverAdapter.cs

Detailed Description

LotSizingDataModel.Solver.Xpress

Optional FICO Xpress MP adapter for LotSizingDataModel.Solver.

The project intentionally avoids a compile-time reference to the Xpress SDK so the public repository and CI remain buildable without a commercial runtime. Runtime discovery is performed only when the adapter is used.

Xpress libraries and license material are not distributed by this repository.

Xpress 9.9 / Optimizer 47.01.01

The installed SDK provides FICO.Xpress.XPRSdn (47.1.1) in C:/xpressmp/lib/nuget. Its managed assembly is xprsdn.dll; the adapter supports this identity as well as legacy Optimizer.dll. Consumers can reference the official package, or set LOTSIZING_XPRESS_OPTIMIZER_ASSEMBLY to the full path of its .NET Standard DLL. Set XPRESSDIR to the installation directory and make the native bin directory available on the process PATH. A valid local Xpress license is required.

Run the optional licensed regression suite with:

dotnet run --project LotSizingDataModel.Solver.Test -c Release -- --xpress-smoke

It checks three shared-resource transport cases (objectives 19 and 37 and an infeasible capacity case), LP minimization/maximization with column-name mapping, integer/binary optimization, and unbounded status. Feasible results are independently checked against variable bounds, integrality, constraints and the objective. The license-free Checker tests additionally reproduce the LP/MIP objective attributes.

Native testing of the published 2.0.0 binaries passed the transport cases but exposed an incorrect LP objective: the adapter read an unset MIP attribute (1E+40) instead of the LP objective. This correction selects LP/MIP attributes by model type, omits incumbent values for infeasible/unbounded results, and reports the SDK version. The published 2.0.0 release is unchanged; these fixes are included in version 2.0.1.