public void SonnetCbcTest2()
{
Console.WriteLine("SonnetCbcTest2 - Cbc set CbcStrategyDefault");
Model model = Model.New("MIP-124725.mps"); // added file to project, "Copy Always"
Solver solver = new Solver(model, typeof(OsiCbcSolverInterface));
model.ObjectiveSense = ObjectiveSense.Minimise;
OsiCbcSolverInterface osisolver = solver.OsiSolver as OsiCbcSolverInterface;
Assert.IsTrue(osisolver != null);
CbcModel cbcModel = osisolver.getModelPtr();
cbcModel.setStrategy(new CbcStrategyDefault(1, 5, 5));
//cbcModel.strategy().setupCutGenerators(cbcModel);
solver.AutoResetMIPSolve = true;
solver.Minimise();
string message = "Used cut generators: " + string.Join(", ", cbcModel.cutGenerators().Select(generator => generator.generator().GetType().Name));
Console.WriteLine(message);
Assert.IsTrue(Utils.EqualsDouble(model.Objective.Value, 124725));
solver.Solve(true);
Assert.IsTrue(Utils.EqualsDouble(model.Objective.Value, 104713.12807881772));
}
public void SonnetCbcTest7()
{
Console.WriteLine("SonnetCbcTest7 - Test CbcModel setObjValue for Maximization");
SonnetLog.Default.LogLevel = 4;
// This test check the improvement of solving when a good solution obj value is given in advance.
// This should help most if the relaxation bound is tight.
Model model = Model.New("mip-124725.mps");
Assert.IsTrue(model.ObjectiveSense == ObjectiveSense.Minimise);
model.Objective = new Objective(-1.0 * (Expression)model.Objective);
model.ObjectiveSense = ObjectiveSense.Maximise;
Solver solver = new Solver(model, typeof(OsiCbcSolverInterface));
OsiCbcSolverInterface osiCbc = solver.OsiSolver as OsiCbcSolverInterface;
osiCbc.AddCbcSolverArgs("-preprocess", "off");
osiCbc.AddCbcSolverArgs("-strong", "0");
osiCbc.AddCbcSolverArgs("-heurist", "off");
osiCbc.AddCbcSolverArgs("-cuts", "off");
solver.Solve();
Assert.IsTrue(solver.IsFeasible());
Assert.IsTrue(solver.IsProvenOptimal, "should be optimal");
solver.Solve();
Assert.IsTrue(solver.IsFeasible());
Assert.IsTrue(solver.IsProvenOptimal, "should be optimal");
// but use at least one solve (or generate and savebefore) to ensure there's something to reset to
solver.AutoResetMIPSolve = false; // dont reset after mip solve, otherwise CbcModel has been reset after solver.Solve()
solver.Solve();
Assert.IsTrue(solver.IsFeasible());
Assert.IsTrue(solver.IsProvenOptimal, "should be optimal");
int nodes1 = osiCbc.getNodeCount();
double objValue1 = model.Objective.Value;
solver.ResetAfterMIPSolve();
osiCbc.Model.setObjValue(-125035.0);
solver.Solve();
Assert.IsTrue(solver.IsFeasible());
Assert.IsTrue(solver.IsProvenOptimal, "should be optimal");
int nodes2 = osiCbc.getNodeCount();
Assert.IsTrue(nodes1 > nodes2, "Providing a feasible obj value must result in improved performance, but number of nodes went from {nodes1} to {nodes2}.");
solver.ResetAfterMIPSolve();
solver.Solve();
Assert.IsTrue(solver.IsFeasible());
Assert.IsTrue(solver.IsProvenOptimal, "should be optimal");
int nodes1b = osiCbc.getNodeCount();
Assert.IsTrue(nodes1 == nodes1b, "Number of nodes should be equal to original but {nodes1} != {nodes1b}.");
// Not advised to use osiCbc.Model.setCutoff Unreliable results especially for Maximisation
}
public void SonnetCbcTest8()
{
Console.WriteLine("SonnetCbcTest8 - Test solver.SetMIPStart");
SonnetLog.Default.LogLevel = 4;
Model model = Model.New("mip-124725.mps");
var objLimit = model.Add((Expression)model.Objective >= 125035.0);
// try get the intermediate solution with value 125035 by adding a constraint and then solving
Solver solver = new Solver(model, typeof(OsiCbcSolverInterface));
solver.Solve();
Assert.IsTrue(solver.IsProvenOptimal, "should be optimal");
Assert.IsTrue(Utils.EqualsDouble(model.Objective.Value, 125035));
// Now the Variable Values represent the solution 125035
// To see the benefit, disable preprocessing etc.
OsiCbcSolverInterface osiCbc = solver.OsiSolver as OsiCbcSolverInterface;
osiCbc.AddCbcSolverArgs("-preprocess", "off");
osiCbc.AddCbcSolverArgs("-strong", "0");
osiCbc.AddCbcSolverArgs("-heurist", "off");
osiCbc.AddCbcSolverArgs("-cuts", "off");
solver.AutoResetMIPSolve = false;
objLimit.Enabled = false; // disable the artificial constraint on objective value
solver.SetMIPStart(true); // take the Variable Values
solver.Solve();
Assert.IsTrue(solver.IsProvenOptimal, "should be optimal");
Assert.IsTrue(solver.IsFeasible());
int nodes1 = osiCbc.getNodeCount(); // nodes using setMIPStart
Assert.IsTrue(Utils.EqualsDouble(model.Objective.Value, 124725));
solver.ResetAfterMIPSolve();
//objLimit.Enabled = true;
//objLimit.Enabled = false;
solver.Solve();
Assert.IsTrue(solver.IsProvenOptimal, "should be optimal");
Assert.IsTrue(solver.IsFeasible());
Assert.IsTrue(solver.IsProvenOptimal, "should be optimal");
int nodes2 = osiCbc.getNodeCount(); // nodes using setMIPStart
Assert.IsTrue(Utils.EqualsDouble(model.Objective.Value, 124725));
Assert.IsTrue(nodes1 < nodes2, "Providing a feasible solution must result in improved performance, but number of nodes went from {nodes1} to {nodes2}.");
}
public void SonnetCbcTest3()
{
Console.WriteLine("SonnetCbcTest3 - Test log message handler vs CbcMain");
Model model = Model.New("MIP-124725.mps"); // added file to project, "Copy Always";
Solver solver = new Solver(model, typeof(OsiCbcSolverInterface));
SonnetLog.Default.LogLevel = 2;
OsiCbcSolverInterface osisolver = solver.OsiSolver as OsiCbcSolverInterface;
//SonnetLog.Default.PassToSolver(osisolver);
Assert.IsTrue(osisolver != null);
CbcModel cbcModel = osisolver.getModelPtr();
solver.Minimise();
Ensure.IsTrue(SonnetLog.Default.LogLevel == 2, "Somehow the SonnetLog LogLevel changed!");
Assert.IsTrue(Utils.EqualsDouble(model.Objective.Value, 124725));
}
public void SonnetCbcTest1()
{
Console.WriteLine("SonnetCbcTest1 - Cbc test set CbcStrategyNull and addCutGenerator");
Model model = Model.New("MIP-124725.mps"); // added file to project, "Copy Always";
Solver solver = new Solver(model, typeof(OsiCbcSolverInterface));
OsiCbcSolverInterface osisolver = solver.OsiSolver as OsiCbcSolverInterface;
Assert.IsTrue(osisolver != null);
CbcModel cbcModel = osisolver.getModelPtr();
cbcModel.setStrategy(new CbcStrategyNull());
cbcModel.addCutGenerator(new CglProbing());
Assert.IsTrue(cbcModel.numberCutGenerators() == 1);
//cbcModel.cutGenerators();
solver.Minimise();
Assert.IsTrue(Utils.EqualsDouble(model.Objective.Value, 124725));
//Assert.IsTrue(Utils.EqualsDouble(model.Objective.Value, 104713.12807881772));
}
public void SonnetCbcTest4()
{
Console.WriteLine("SonnetCbcTest4 - Test CbcModel with args to stop after solution");
SonnetLog.Default.LogLevel = 0;
SonnetLog.Default.Debug("Log Debug");
SonnetLog.Default.Info("Log Info");
SonnetLog.Default.Warn("Log Warn");
SonnetLog.Default.Error("Log Error");
Model model = Model.New("mas74.mps");
Expression obj = (Expression)model.Objective;
obj.Add(10000.0); // check that the objective constant is taken into account.
model.Objective = obj;
Solver solver = new Solver(model, typeof(OsiCbcSolverInterface));
OsiCbcSolverInterface osiCbc = solver.OsiSolver as OsiCbcSolverInterface;
osiCbc.getModelPtr().setMaximumSeconds(5.0); // Stop within 5 seconds
solver.Solve();
Assert.IsTrue(solver.IsFeasible(), "with solution and hence feasible");
Assert.IsFalse(solver.IsProvenOptimal, "should not be optimal yet (unless solver got a lot better)");
Assert.IsTrue(model.Objective.Bound < model.Objective.Value, "Bound must be less than current solution.");
// The problem is minimization.
// Allow also better solutions, but not worse.
// If your machine is significantly slower, the solution value will be worse (higher) and this test will fail--but can be ignored.
Assert.IsTrue(model.Objective.Value >= 21801.18 && model.Objective.Value <= 22465, $"Best minimization solution of mas74 until now is ${model.Objective.Value} but should be between 21801.18 (opt) and 22465");
// bound is expected to be 20482 on the reference machine.
// If your machine is slower, the bound will be worse (lower)
// If your machine is faster, the bound could be better (higher)
Assert.IsTrue(model.Objective.Bound >= 20300.0 && model.Objective.Bound <= 20700.0, $"Bound (Gap) is now ${model.Objective.Bound} but should be betweeen 20300 and 20700");
}
public void SonnetCbcTest5()
{
Console.WriteLine("SonnetCbcTest5 - Test CbcModel Event Handler");
SonnetLog.Default.LogLevel = 4;
SonnetLog.Default.Debug("Log Debug");
SonnetLog.Default.Info("Log Info");
SonnetLog.Default.Warn("Log Warn");
SonnetLog.Default.Error("Log Error");
Model model = Model.New("mas74.mps");
Solver solver = new Solver(model, typeof(OsiCbcSolverInterface));
OsiCbcSolverInterface osiCbc = solver.OsiSolver as OsiCbcSolverInterface;
osiCbc.getModelPtr().setMaximumSeconds(5.0); // Stop within 5 seconds
CbcEventHandler handler = delegate(CbcModel m, CbcEvent cbcEvent) { return(CbcAction.noAction); };
handler += new CbcEventHandler(SonnetCbcTest5EventHandler); // will stop after 2nd solution
osiCbc.Model.passInEventHandler(handler); //
int numCalls = 0;
CbcSolver.CallBack = delegate(CbcModel m, int whereFrom) { numCalls++; return(0); };
solver.Solve();
// DONT use the cbcModel after solver.Solve() because of ResetAfterMIPSolveInternal at the end of Solve()
Assert.IsTrue(solver.IsFeasible());
Assert.IsFalse(solver.IsProvenOptimal, "should not be optimal yet");
Assert.IsTrue(SonnetCbcTest5numSolutions >= 2, "should have found at least two solutions by now");
Assert.IsTrue(numCalls == 5);
// Allow also better solutions, but not worse. The problem is minimization.
// If you machine is significantly slower, the solution will be worse and this test will fail--but can be ignored.
Assert.IsTrue(model.Objective.Value >= 11801.18 && model.Objective.Value <= 14168.34, $"Best minimization solution of mas74 until now is ${model.Objective.Value} but should be between 11801.18 (opt) and 14168.34");
}
