LpSolveDotNet

LpSolveDotNet is a .NET wrapper for the Mixed Integer Linear Programming (MILP) solver lp_solve. The wrapper works with both 32-bit and 64-bit applications.

The solver lp_solve solves pure linear, (mixed) integer/binary, semi-cont and special ordered sets (SOS) models.

Usage

To use LpSolveDotNet follow these steps:

1. Add NuGet package LpSolveDotNet to your project using NuGet Package Manager: Install-Package LpSolveDotNet. This will
   • Add a reference to the LpSolveDotNet library
   • Add a post-build step to your project file that will copy the native library lpsolve55.dll to your output folder. Note that this will copy both the 32-bit and 64-bit versions of the library and LpSolveDotNet will load the correct one at runtime.
2. In your project, add a call to either of the LpSolveDotNet.LpSolve.Init() methods defined below. Both of them will modify the PATH environment variable of the current process to allow it to find the lpsolve methods. Note that calling multiple times these methods has no side effects (unless you pass different parameters).
   • Init(dllFolderPath): This method will use the given dllFolderPath to find lpsolve55.dll.
   • Parameterless Init(): This method will determine where is lpsolve55.dll based on IntPtr.Size, using either NativeBinaries\win64 or NativeBinaries\win32 relative to executing assembly.
3. Use one of the factory methods on LpSolve class to create an LpSolve instance:
   • make_lp
   • read_LP
   • read_freeMPS
   • read_MPS
   • read_XLI
4. Place the returned LpSolve instance into a using statement so it is properly disposed of when done with it.
5. Use methods on that instance. The methods are like the official lpsolve documentation except the first parameter which is passed implicitly by this instance.

In a future version, there will be documentation on the methods and the API will look more like .NET than C. Don't worry the old syntax will stay there.

Examples

You can see examples in the Demo project translated from lpsolve's original C# samples.

• Formulation of an lp model in lpsolve
• demo inside lp_solve_5.5.2.3_cs.net.zip

Releases

You can see the release history.