IMsControlProblem.Constraints

Syntax

Description

The Constraints property returns the collection of constraints for criterion function.

Comments

To set the object, to which optimal values will be loaded, use the IMsControlProblem.OptimalVariable property.

Example

Executing the example requires that the repository contains a modeling container with the MS identifier. This container should contain a folder with the CONTROLPROBLEM_FOLDER identifier and a metamodel with the CONTROL_METAMODEL identifier. The specified metamodel should contain a model with the CONTROL_MODEL identifier containing several factors.

Add links to the Cp, Dimensions, Metabase, Ms system assemblies.

Sub UserProc;
Var
    MB: IMetabase;
    MsObj: IMetabaseObjectDescriptor;
    CrInf: IMetabaseObjectCreateInfo;
    MObj: IMetabaseObject;
    Problem: IMsProblem;
    MetaModel: IMsMetaModel;
    ScenarioTree: IMsScenarioTreeEntries;
    Scenario: IMsScenario;
    ControlProblem: IMsControlProblem;
    CPModel, Model: IMsModel;
    CPTransform: IMsFormulaTransform;
    CPOutputs, Inputs, CPInputs: IMsFormulaTransformVariables;
    ControlsList, CFList: IMsFormulaTermList;
    ConstrTerm, CFTerm: IMsFormulaTerm;
    FactorVar, ControlVar, CFVar: IMsFormulaTransformVariable;
    Slice: IMsFormulaTransformSlice;
    ControlTerm: IMsNonLinearControlFormulaTerm;
    Constrs: IMsNonLinearConstraints;
    Constr: IMsNonLinearConstraint;
    MsKey: Integer;
    Period: IMsModelPeriod;
    s: String;
    i: Integer;
Begin
    // Get current repository
    MB := MetabaseClass.Active;
    // Get modeling container
    MsObj := Mb.ItemById("MS").Edit;
    MsKey := MsObj.Key;
    // Create the Modeling Problem object
    CrInf := Mb.CreateCreateInfo;
    CrInf.ClassId := MetabaseObjectClass.KE_CLASS_MSPROBLEM;
    CrInf.Id := MB.GenerateId("CONTROL_PROBLEM", MsKey);
    CrInf.Name := "Optimal control problem";
    CrInf.Parent := MB.ItemByIdNamespace("CONTROLPROBLEM_FOLDER", MsKey);
    MObj := Mb.CreateObject(CrInf).Edit;
    Problem := MObj As IMsProblem;
    // Determine metamodel calculated by problem
    MetaModel := MB.ItemByIdNamespace("CONTROL_METAMODEL", MsKey).Bind As IMsMetaModel;
    Problem.MetaModel := MetaModel;
    // Get modeling container scenario
    ScenarioTree := (MsObj As IMsModelSpace).ScenarioTree;
    // Add a scenario
    Scenario := (ScenarioTree.AddScenario).Scenario;
    // Add created scenario to modeling problem
    Problem.Scenarios.AddScenario(Scenario);
    // Create calculation parameters of optimal control problem
    ControlProblem := New MsControlProblem.Create;
    // Specify that the created modeling problem has the "Optimal Control Problem" type
    Problem.Details := ControlProblem;
    // Set basic parameters of optimal control problem
    ControlProblem.Extremum := ExtremumType.Minimum;
    ControlProblem.MaxIterationsCount := 100000;
    ControlProblem.MethodType := CpNonLinearMethodType.SequentialQP;
    ControlProblem.Level := DimCalendarLevel.Year;
    ControlProblem.Tolerance := 0.005;
    // Get a model containing criterion function parameters
    CPModel := ControlProblem.Model;
    // Get output variable
    CPTransform := CPModel.Transform;
    CPOutputs := CPTransform.Outputs;
    // Determine that optimal values of criterion function will be loaded to output variable
    ControlProblem.OptimalVariable := CPOutputs.Item(0).VariableStub As IMsVariable;
    // Get collection of controlling variables
    ControlsList := ControlProblem.ControlVariables;
    // Get model calculated with modeling problem
    Model := (MetaModel.CalculationChain.FindById("CONTROL_MODEL") As IMsCalculationChainModel).Model;
    // Get collection of model factors
    Inputs := Model.Transform.Inputs;
    // Add all model factors to collection of controlling variables
    For i := 0 To Inputs.Count - 1 Do
        FactorVar := Inputs.Item(i);
        CPInputs := CPTransform.Inputs;
        ControlVar := CPInputs.Add(FactorVar.VariableStub);
        Slice := ControlVar.Slices.Add(FactorVar.Slices.Item(0).Selection);
        // Set limits of controlling variables
        ControlTerm := ControlsList.Add(Slice) As IMsNonLinearControlFormulaTerm;
        ControlTerm.UseLowerBound := True;
        ControlTerm.LowerBound := 0 - i * 0.1;
        ControlTerm.UseUpperBound := True;
        ControlTerm.UpperBound := 1 + i * 0.1;
    End For;
    // Get collection of variables to compose criterion function
    CFList := ControlProblem.Operands;
    // Add a variable to collection
    CFVar := CPInputs.Item(0);
    Slice := CFVar.Slices.Item(0);
    CFTerm := CFList.Add(Slice);
    // Compose criterion function
    s := CFTerm.TermToInnerText + " + 0.5";
    ControlProblem.CriterionFunction.AsString := s;
    // Get collection of criterion function constraints
    Constrs := ControlProblem.Constraints;
    // Add a constraint
    Constr := Constrs.Add;
    ConstrTerm := Constr.Operands.Add(Slice);
    Constr.Expression.AsString := ConstrTerm.TermToInnerText;
    Constr.LowerBound.AsString := "-100";
    Constr.UpperBound.AsString := "100";
    // Set calculation period
    Period := ControlProblem.Period;
    Period.IdentificationStartDate := DateTime.Parse("01.01.1990");
    Period.IdentificationEndDate := DateTime.Parse("31.12.2011");
    Period.ForecastStartDate := DateTime.Parse("01.01.2012");
    Period.ForecastEndDate := DateTime.Parse("31.12.2018");
    // Save changes
    MObj.Save;
    (MsObj As IMetabaseObject).Save;
End Sub UserProc;

After executing the example a new optimal control problem is created in the CONTROLPROBLEM_FOLDER folder of modeling container. The metamodel, scenario, variable are added to the problem for making of criterion function. The criterion function is created, for which the minimum value is determined during problem calculation. The quadratic programming method is used for calculation. The controlling variable and one constraint for criterion function is added. The minimum number of iterations and accuracy of solution search are set.