private static void RunLinearProgrammingExampleNaturalApi(String solverType)
{
Solver solver = Solver.CreateSolver("IntegerProgramming", solverType);
if (solver == null)
{
Console.WriteLine("Could not create solver " + solverType);
return;
}
// x1, x2 and x3 are continuous non-negative variables.
Variable x1 = solver.MakeNumVar(0.0, double.PositiveInfinity, "x1");
Variable x2 = solver.MakeNumVar(0.0, double.PositiveInfinity, "x2");
Variable x3 = solver.MakeNumVar(0.0, double.PositiveInfinity, "x3");
solver.Maximize(10 * x1 + 6 * x2 + 4 * x3);
Constraint c0 = solver.Add(x1 + x2 + x3 <= 100);
Constraint c1 = solver.Add(10 * x1 + x2 * 4 + 5 * x3 <= 600);
Constraint c2 = solver.Add(2 * x1 + 2 * x2 + 6 * x3 <= 300);
Console.WriteLine("Number of variables = " + solver.NumVariables());
Console.WriteLine("Number of constraints = " + solver.NumConstraints());
int resultStatus = solver.Solve();
// Check that the problem has an optimal solution.
if (resultStatus != Solver.OPTIMAL)
{
Console.WriteLine("The problem does not have an optimal solution!");
return;
}
Console.WriteLine("Problem solved in " + solver.WallTime() +
" milliseconds");
// The objective value of the solution.
Console.WriteLine("Optimal objective value = " +
solver.Objective().Value());
// The value of each variable in the solution.
Console.WriteLine("x1 = " + x1.SolutionValue());
Console.WriteLine("x2 = " + x2.SolutionValue());
Console.WriteLine("x3 = " + x3.SolutionValue());
Console.WriteLine("Advanced usage:");
Console.WriteLine("Problem solved in " + solver.Iterations() +
" iterations");
Console.WriteLine("x1: reduced cost = " + x1.ReducedCost());
Console.WriteLine("x2: reduced cost = " + x2.ReducedCost());
Console.WriteLine("x3: reduced cost = " + x3.ReducedCost());
Console.WriteLine("c0: dual value = " + c0.DualValue());
Console.WriteLine(" activity = " + c0.Activity());
Console.WriteLine("c1: dual value = " + c1.DualValue());
Console.WriteLine(" activity = " + c1.Activity());
Console.WriteLine("c2: dual value = " + c2.DualValue());
Console.WriteLine(" activity = " + c2.Activity());
}
/**
*
* Volsay problem.
*
* From the OPL model volsay.mod.
*
*
* Also see http://www.hakank.org/or-tools/volsay.py
*
*/
private static void Solve()
{
Solver solver = new Solver("Volsay", Solver.CLP_LINEAR_PROGRAMMING);
//
// Variables
//
Variable Gas = solver.MakeNumVar(0, 100000, "Gas");
Variable Chloride = solver.MakeNumVar(0, 100000, "Cloride");
Constraint c1 = solver.Add(Gas + Chloride <= 50);
Constraint c2 = solver.Add(3 * Gas + 4 * Chloride <= 180);
solver.Maximize(40 * Gas + 50 * Chloride);
int resultStatus = solver.Solve();
if (resultStatus != Solver.OPTIMAL)
{
Console.WriteLine("The problem don't have an optimal solution.");
return;
}
Console.WriteLine("Objective: {0}", solver.ObjectiveValue());
Console.WriteLine("Gas : {0} ReducedCost: {1}",
Gas.SolutionValue(),
Gas.ReducedCost());
Console.WriteLine("Chloride : {0} ReducedCost: {1}",
Chloride.SolutionValue(),
Chloride.ReducedCost());
Console.WriteLine("c1 : DualValue: {0} Activity: {1}",
c1.DualValue(),
c1.Activity());
Console.WriteLine("c2 : DualValue: {0} Activity: {1}",
c2.DualValue(),
c2.Activity());
Console.WriteLine("\nWallTime: " + solver.WallTime());
Console.WriteLine("Iterations: " + solver.Iterations());
}
