How to Use - Long Version

Library Initialization

Before LpSolveDotNet can be used, it needs to be initialized properly so it loads the native library of lp_solve for your platform.

Standard Usage

Find the package name for your target platform(s) in the table below and add it (them) to your project. The LpSolveDotNet.Native.??? packages, which reference the LpSolveDotNet package, will not only add the .NET wrapper of the lp_solve library, it will also take care of copying the native library to your build output.

Other OS / Architectures

If your application runs on an OS / Architecture that is not listed above, you need to do the following:

1. Build lp_solve for your OS / Architecture combination.
2. Deploy the built native library alongside your application
3. If your application does not load lp_solve properly, you may need to look at Other .NET Targets section for further instructions.
4. If you did not put the native library in a folder in the paths searched by the .NET implementation, tweak the arguments you pass to LpSolveDotNet.LpSolve.Init() when you call it to match your case.

Other .NET Targets

If building your application resolves to use LpSolveDotNet's .NET Stantards targets (with an app targeting .NET Core earlier than 3.0, Xamarin...), the library will not pick up the native library by itself. The different ways to fix this are (pick one):

1. Using property LpSolveDotNet.LpSolve.CustomLoadNativeLibrary
   1. Create a method that takes in a file path and enables your .NET implementation to load it
   2. Assign this method to the property LpSolveDotNet.LpSolve.CustomLoadNativeLibrary
2. Placing the native library in a folder in the paths searched by the .NET implementation. This could also be what your method LpSolveDotNet.LpSolve.CustomLoadNativeLibrary is doing.
3. Tweak the arguments you pass to LpSolveDotNet.LpSolve.Init() when you call it to match your case.

Complete the initialization

To complete the initialization from previous steps, your code must call once the LpSolveDotNet.LpSolve.Init() method. This will ensure that the right native library is loaded and called.

Using the library

1. Use one of the factory methods on LpSolve class to create an LpSolve instance:
   • make_lp
   • read_LP
   • read_MPS
   • read_XLI
2. Place the returned LpSolve instance into a using statement so it is properly disposed of when done with it.
3. Use methods on that instance like the example in How to Use - Short Version or those in the Demo project.

More documentation

• Online documentation
• official lp_solve documentation, the LpSolveDotNet's LpSolve object has the same methods as lp_solve API except the first parameter lprec *lp which is passed implicitly instead.

In a future version, the API will be more idiomatic to .NET instead of looking like C. Don't worry, we'll keep backwards compatibility so your existing code will continue to compile as-is.

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

Feedback

LpSolve is released as open source under the LGPL-2.1 license. Bug reports and contributions are welcome at the GitHub repository.