Class GurobiSolver

A wrapper class to access Gurobi as a solver

Inheritance
System.Object
SolverBase
GenericSolverBase<GurobiSolverConfiguration>
GurobiSolver
Inherited Members
System.Object.ToString()
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
Namespace: OPTANO.Modeling.Optimization.Solver.Gurobi752
Assembly: Optimization.Solver.Gurobi752.dll
Syntax
public class GurobiSolver : GenericSolverBase<GurobiSolverConfiguration>, ISolver, ICanSolve<Model, Solution>, IAbortable, ICanManipulateANativeSolver, IDisposable, ICanHandleUserSolution, IStatus<StatusInfo>

Constructors

GurobiSolver(GurobiSolverConfiguration)

Initializes a new instance of the GurobiSolver class. This solver utilizes the native multiobjective optimization of Gurobi 7.52. Tries to acquire a Gurobi License. If this fails, a Gurobi.GRBException is thrown. In order to use the GurobiSolver in your project, make sure to reference the GurobiXX.NET.dll from your gurobi installation folder ('..\gurobiXX\win64\bin\GurobiXX.NET.dll')

Declaration
public GurobiSolver(GurobiSolverConfiguration configuration = null)
Parameters
Type Name Description
GurobiSolverConfiguration configuration

The configuration.

Methods

Abort()

If this solver instance , abort the run as soon as possible, or do nothing if this solver instance is not busy.

Declaration
public override void Abort()
Overrides
Exceptions
Type Condition
System.NotSupportedException

If this solver instance does not support aborting.

AddConstraint(Constraint)

The add constraint.

Declaration
[Obsolete("Consider using batch method AddConstraints.", false)]
protected void AddConstraint(Constraint constraint)
Parameters
Type Name Description
Constraint constraint

The constraint.

AddConstraints(IEnumerable<Constraint>)

Declaration
protected void AddConstraints(IEnumerable<Constraint> constraintsEnumerable)
Parameters
Type Name Description
System.Collections.Generic.IEnumerable<Constraint> constraintsEnumerable

AddObjective(Objective)

The add single objective method is not supported for GurobiSolver 7.0

Declaration
protected override void AddObjective(Objective objective)
Parameters
Type Name Description
Objective objective

The objective.
Overrides
Exceptions
Type Condition
System.ArgumentNullException

objective mustn't be null.
System.NotSupportedException

This operation is not supported.

BuildSolverModelAdapterSpecific(Int32)

Solves the specified CurrentModel. If specified in CopySolutionToModel, the results of a solved Model will automatically be written in the OPTANO.Modeling's Variables.

Declaration
protected override void BuildSolverModelAdapterSpecific(int prioLevel = 0)
Parameters
Type Name Description
System.Int32 prioLevel

The priority level to solve for.
Overrides

CanExportFile(FileInfo, ExportTime, Boolean)

True, if ModelOutputFile is not null and has any extension.

Declaration
protected override bool CanExportFile(FileInfo outputFile, ExportTime exportTime, bool printHints = false)
Parameters
Type Name Description
System.IO.FileInfo outputFile

The file to check.
ExportTime exportTime

Export before or after solve.
System.Boolean printHints

Indicates whether to print hints.
Returns
Type Description
System.Boolean

The System.Boolean.
Overrides

ClearLastModel()

Deletes the internal datastructures of this SolverBase instance.

Declaration
public override void ClearLastModel()
Overrides
Exceptions
Type Condition
System.InvalidOperationException

If this SolverBase instance .

Dispose(Boolean)

Disposes this instance of the GurobiSolver. Frees the Gurobi License.

Declaration
protected void Dispose(bool freeManagedObjectsAlso)
Parameters
Type Name Description
System.Boolean freeManagedObjectsAlso

True, if managed objects such as the Gurobi.GRBEnv should be disposed as well.

DisposeCustom()

Disposes this instance of . Frees the Gurobi License

Declaration
protected override void DisposeCustom()
Overrides

ExportFileSolverSpecific(FileInfo)

Export the model solver specific.

Declaration
protected override void ExportFileSolverSpecific(FileInfo outputFile)
Parameters
Type Name Description
System.IO.FileInfo outputFile
Overrides

Finalize()

Finalizes an instance of the GurobiSolver class. Frees the Gurobi License

Declaration
protected void Finalize()

GetSubOptimalSolution(Int32)

The get sub optimal solution.

Declaration
public Dictionary<string, double> GetSubOptimalSolution(int n)
Parameters
Type Name Description
System.Int32 n

The index of the solution that is queried.
Returns
Type Description
System.Collections.Generic.Dictionary<System.String, System.Double>

The solution values, identified by Name.
Exceptions
Type Condition
System.ArgumentException

Thrown, if there are less than n suboptimal solutions.

RebuildSolverModelAdapterSpecific(Int32)

Empty rebuild method, as Gurobi Solver can handle resolves.

Declaration
protected override void RebuildSolverModelAdapterSpecific(int prioLevel = 0)
Parameters
Type Name Description
System.Int32 prioLevel

Not used for native multi objective solver.
Overrides

RemoveConstraint(String)

Removes the Constraint with Name == name.

Declaration
protected override void RemoveConstraint(string name)
Parameters
Type Name Description
System.String name

The name of the Constraint to remove.
Overrides

ResolveAdapterSpecific(Int32, IDictionary<Variable, Double>)

Performs a Gurobi specific resolve for the CurrentModel. Make sure that this method is only called, in case of an actual resolve. Otherwise, the internal Gurobi.GRBModel will throw an Gurobi.GRBException.

Declaration
protected override Solution ResolveAdapterSpecific(int prioLevel = 0, IDictionary<Variable, double> variableValues = null)
Parameters
Type Name Description
System.Int32 prioLevel

The priority level to solve for.
System.Collections.Generic.IDictionary<Variable, System.Double> variableValues

The start values.
Returns
Type Description
Solution

The Solution.
Overrides

SetBranchingPriorityAdapterSpecific()

Set the BranchingPriority for all variables. Expects Gurobi.GRBModel to be up to date. Updates the Gurobi.GRBModel afterwards.

Declaration
protected override void SetBranchingPriorityAdapterSpecific()
Overrides

SetConfigurationAdapterSpecific()

Sets the solver configuration. This includes all values specified in GurobiSolverConfiguration and the following values: The values for MIPGap, MIPGapAbs, and TimeLimit are taken from the base SolverConfiguration and set every time when this method is executed. Before, the values only were set when the user specifically specified any value other than 0.

Declaration
protected override void SetConfigurationAdapterSpecific()
Overrides

SolveAdapterSpecific(Int32, IDictionary<Variable, Double>)

Solves the specified CurrentModel. If specified in CopySolutionToModel, the results of a solved Model will automatically be written in the OPTANO.Modeling's Variables.

Declaration
protected override Solution SolveAdapterSpecific(int prioLevel = 0, IDictionary<Variable, double> variableValues = null)
Parameters
Type Name Description
System.Int32 prioLevel

This parameter is ignored for solvers that have a native support for multiple objectives.
System.Collections.Generic.IDictionary<Variable, System.Double> variableValues

The starting values to pass as initial solution.
Returns
Type Description
Solution

The Solution. Before accessing the VariableValues, make sure that the Model is Feasible and the Solution is Feasible or Optimal.
Overrides

Events

Status

The status callback during the solution process.

Declaration
public event Action<StatusInfo> Status
Event Type
Type Description
System.Action<StatusInfo>
Implements

Explicit Interface Implementations

ICanHandleUserSolution.ClearPendingUserSolutions()

Declaration
void ICanHandleUserSolution.ClearPendingUserSolutions()
Implements

ICanHandleUserSolution.EnqueueUserSolution(Dictionary<String, Double>)

Declaration
void ICanHandleUserSolution.EnqueueUserSolution(Dictionary<string, double> userSolution)
Parameters
Type Name Description
System.Collections.Generic.Dictionary<System.String, System.Double> userSolution
Implements

ICanHandleUserSolution.PendingUserSolutionCount

Declaration
int ICanHandleUserSolution.PendingUserSolutionCount { get; }
Returns
Type Description
System.Int32
Implements

ICanHandleUserSolution.ReplaceAllPendingSolutions(Dictionary<String, Double>)

Declaration
void ICanHandleUserSolution.ReplaceAllPendingSolutions(Dictionary<string, double> userSolution)
Parameters
Type Name Description
System.Collections.Generic.Dictionary<System.String, System.Double> userSolution
Implements

Extension Methods