Try our new documentation site (beta).


/* Copyright 2021, Gurobi Optimization, LLC */

/* This example creates a very simple Special Ordered Set (SOS) model.
   The model consists of 3 continuous variables, no linear constraints,
   and a pair of SOS constraints of type 1. */

using System;
using Gurobi;

class sos_cs
  static void Main()
    try {
      GRBEnv env = new GRBEnv();

      GRBModel model = new GRBModel(env);

      // Create variables

      double[] ub    = {1, 1, 2};
      double[] obj   = {-2, -1, -1};
      string[] names = {"x0", "x1", "x2"};

      GRBVar[] x = model.AddVars(null, ub, obj, null, names);

      // Add first SOS1: x0=0 or x1=0

      GRBVar[] sosv1  = {x[0], x[1]};
      double[] soswt1 = {1, 2};

      model.AddSOS(sosv1, soswt1, GRB.SOS_TYPE1);

      // Add second SOS1: x0=0 or x2=0

      GRBVar[] sosv2  = {x[0], x[2]};
      double[] soswt2 = {1, 2};

      model.AddSOS(sosv2, soswt2, GRB.SOS_TYPE1);

      // Optimize model


      for (int i = 0; i < 3; i++)
        Console.WriteLine(x[i].VarName + " " + x[i].X);

      // Dispose of model and env

    } catch (GRBException e) {
      Console.WriteLine("Error code: " + e.ErrorCode + ". " + e.Message);

Try Gurobi for Free

Choose the evaluation license that fits you best, and start working with our Expert Team for technical guidance and support.

Evaluation License
Get a free, full-featured license of the Gurobi Optimizer to experience the performance, support, benchmarking and tuning services we provide as part of our product offering.
Academic License
Gurobi supports the teaching and use of optimization within academic institutions. We offer free, full-featured copies of Gurobi for use in class, and for research.
Cloud Trial

Request free trial hours, so you can see how quickly and easily a model can be solved on the cloud.