Class Model

Represents a mathematical model

Inheritance

System.Object

Model

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

Assembly: Optimization.dll

Syntax

[DataContract]
[Serializable]
public class Model : ICanRegisterSolvers, ICanTrackPropertyChangesInVariables, ICanTrackPropertyChangesInConstraints

Constructors

Model()

Initializes a new instance of the Model class.

Declaration

public Model()

Exceptions

Type	Condition
System.InvalidOperationException	Model requires Current != null.

Model(String)

Initializes a new instance of the Model class.

Declaration

public Model(string name)

Parameters

Type	Name	Description
System.String	name	The model name.

Exceptions

Type	Condition
System.InvalidOperationException	Model requires Current != null.

Properties

AreAllConstraintsLinear

Have all constraints in this model instance linear expressions?

Declaration

public bool AreAllConstraintsLinear { get; }

Property Value

Type	Description
System.Boolean

AreAllVariablesBinary

Are all variables in this model instance of type Binary? A Binary variable is a special case of an Integer variable, where the bounds are in the range of [0, 1].

Declaration

public bool AreAllVariablesBinary { get; }

Property Value

Type	Description
System.Boolean

AreAllVariablesContinuous

Are variables in this model instance of type Continuous?

Declaration

public bool AreAllVariablesContinuous { get; }

Property Value

Type	Description
System.Boolean

AreAllVariablesInteger

Are all variables in this model instance of type Integer?

Declaration

public bool AreAllVariablesInteger { get; }

Property Value

Type	Description
System.Boolean

Constraints

Constraints in this model instance.

Declaration

public IEnumerable<Constraint> Constraints { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<Constraint>

ConstraintsCount

Gets the count of constraints in this model instance.

Declaration

public int ConstraintsCount { get; }

Property Value

Type	Description
System.Int32

IsMultiObectiveModel

Gets a value indicating whether this Model contains multiple Objective fcuntions.

Declaration

public bool IsMultiObectiveModel { get; }

Property Value

Type	Description
System.Boolean

IsMultiStageModel

Gets a value indicating whether this Model contains multiple optimization stages.

Declaration

public bool IsMultiStageModel { get; }

Property Value

Type	Description
System.Boolean

IsObjectiveLinear

Has the objective in this model instance a linear expression

Declaration

public bool IsObjectiveLinear { get; }

Property Value

Type	Description
System.Boolean	true if objective is linear, false if objective is null or non-linear

Name

Name of this model instance.

Declaration

[DataMember]
public string Name { get; set; }

Property Value

Type	Description
System.String

NotifySolversIfModelChanges

If set to true (standard value), will communicate the changes made to this model directly to all solver instances that have previously solved this model.

Declaration

public bool NotifySolversIfModelChanges { get; set; }

Property Value

Type	Description
System.Boolean	true if model should notify all solvers; otherwise, false.

Objective

Objectives for this model instance.

Declaration

[Obsolete("Please consider using the AddObjective function in order to enable support for multiobjective optimization.", false)]
public Objective Objective { get; set; }

Property Value

Type	Description
Objective

Objectives

Gets the objectives.

Declaration

public IEnumerable<Objective> Objectives { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<Objective>

ObjectivesCount

Gets the count of objectives in this model instance.

Declaration

public int ObjectivesCount { get; }

Property Value

Type	Description
System.Int32

ObjectiveStagesCount

Gets the count of objective stages in this model instance.

Declaration

public int ObjectiveStagesCount { get; }

Property Value

Type	Description
System.Int32

ObjectiveStagesOrdered

Gets the objective stages in optimization order. I.e. the objective with highest priority is returned first.

Declaration

public IEnumerable<int> ObjectiveStagesOrdered { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<System.Int32>

OperatorConstraints

Gets the Operator Constraints in this model instance. The OperatorConstraints will be transformed into supported constraints before a model is passed to the solver.

Declaration

public IEnumerable<OperatorConstraint> OperatorConstraints { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<OperatorConstraint>

PriorityLevels

Gets the distinct set of priority levels, ordered descending.

Declaration

public IEnumerable<int> PriorityLevels { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<System.Int32>

SOS1Sets

Sets of S1 variables in this model instance. The Value of each entry indicates the weight for the variable in its SOS.

Declaration

public IEnumerable<Dictionary<Variable, double>> SOS1Sets { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<System.Collections.Generic.Dictionary<Variable, System.Double>>

SOS2Sets

Sets of S2 variables in this model instance. The Value of each entry indicates the weight for the variable in its SOS. It is used to determine the variable ordering in a SOS of type S2.

Declaration

public IEnumerable<Dictionary<Variable, double>> SOS2Sets { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<System.Collections.Generic.Dictionary<Variable, System.Double>>

SOS3Sets

Sets of S3 variables in this model instance. The Value of each entry indicates the weight for the variable in its SOS.

Declaration

public IEnumerable<Dictionary<Variable, double>> SOS3Sets { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<System.Collections.Generic.Dictionary<Variable, System.Double>>

UnhandledVariables

Gets all variables that are not handled by the variable collection that are registered to this model.

Declaration

public IEnumerable<Variable> UnhandledVariables { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<Variable>	The set of unhandled variables.

VariableCollections

The get variable collection enumerator.

Declaration

public IEnumerable<VariableCollection> VariableCollections { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<VariableCollection>	The System.Collections.IEnumerable. An enumerable, that contains all variable collections that are registered to this model

Variables

Variables in this model instance.

Declaration

public IEnumerable<Variable> Variables { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<Variable>

VariablesCount

Gets the count of variables in this model instance.

Declaration

public int VariablesCount { get; }

Property Value

Type	Description
System.Int32

VariablesRemovedDuringPreProcessing

Returns the variables that were removed during pre-processing. Can be null, if ComputeRemovedVariables is disabled, or if the chosen Solver does not support the computation.

Declaration

public IEnumerable<Variable> VariablesRemovedDuringPreProcessing { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<Variable>

VariableStatistics

Gets additional variable statistics for all variables that are registered to this model. Refer to the Model Feature section that is described in the OPTANO.Modeling User Documentation for further information.

Declaration

public HashSet<VariableStatisticRow> VariableStatistics { get; }

Property Value

Type	Description
System.Collections.Generic.HashSet<VariableStatisticRow>	The System.Collections.Generic.HashSet<T>. All variable statistics

Methods

Abs(Expression, Double)

Returns an Expression object respresenting the absolute value of the specified expression.

Declaration

public static Expression Abs(Expression expression, double bigM = 1.7976931348623157E+308)

Parameters

Type	Name	Description
Expression	expression	The expression.
System.Double	bigM	Large number, only used if the bounds of the variables of the expressions are non-finite

Returns

Type	Description
Expression	An expression that represents the absolute of the given expression.

Abs(Term, Double)

Returns an Expression object respresenting the absolute value of the specified expression.

Declaration

public static Expression Abs(Term expression, double bigM = 1.7976931348623157E+308)

Parameters

Type	Name	Description
Term	expression	The expression.
System.Double	bigM	Large number, only used if the bounds of the variables of the expressions are non-finite

Returns

Type	Description
Expression	An expression that represents the absolute of the given term.

AddAlternativeConstraintGroups(IEnumerable<Constraint>, IEnumerable<Constraint>, Double)

Adds two groups of constraints. Either group1 or group2 or both have to be fulfilled in a valid solution

Declaration

public void AddAlternativeConstraintGroups(IEnumerable<Constraint> group1, IEnumerable<Constraint> group2, double bigM)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<Constraint>	group1	The one group of constraints
System.Collections.Generic.IEnumerable<Constraint>	group2	The other group of constraints
System.Double	bigM	The big M to use in reformulation

AddAlternativeConstraints(Dictionary<Constraint, Double>)

Adds constraints that are OR concatenated. That means that at least one of these constraints have to be fulfilled. For every constraint l<=exp<=u in constraints this method will add the following two constraints to your model:

-exp-bigM*(1-z1)<=-l and

exp-bigM*(1-z1)<=u,

where z is a binary variable indicating that this constraint is active (has to be fulfilled). Since this will happen for every constraint in the list of constraints, the binary variables z will be summed up in one additional constraint, such that expression.Sum(z1,...,zn)>=1 For each constraint you will have to provide a bigM value.

Declaration

public void AddAlternativeConstraints(Dictionary<Constraint, double> constraintBigMPairs)

Parameters

Type	Name	Description
System.Collections.Generic.Dictionary<Constraint, System.Double>	constraintBigMPairs	The constraints and a bigM for each constraint.

AddAlternativeConstraints(IEnumerable<Constraint>)

Adds constraints that are OR concatenated. That means that at least one of these constraints have to be fulfilled. For every constraint l<=exp<=u in constraints this method will add the following two constraints to your model:

-exp-bigM*(1-z1)<=-l and

exp-bigM*(1-z1)<=u,

where z is a binary variable indicating that this constraint is active (has to be fulfilled). Since this will happen for every constraint in the list of constraints, the binary variables z will be summed up in one additional constraint, such that Expression.Sum(z1,...,zn)>=1 The bigM will be computed for you, but this can only happen when you provide finite bounds on all variables that are used in your constraints.

Declaration

public void AddAlternativeConstraints(IEnumerable<Constraint> constraints)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<Constraint>	constraints

AddConstraint(Constraint)

Adds constraint to this model instance if it is consistent. You need to make sure that the name of the constraint is unique.

Declaration

public void AddConstraint(Constraint constraint)

Parameters

Type	Name	Description
Constraint	constraint	Constraint to add, constraint may not be null

AddConstraint(Constraint, String)

Adds constraint to this model instance if it is consistent. You need to make sure that the name of the constraint is unique.

Declaration

public void AddConstraint(Constraint constraint, string name)

Parameters

Type	Name	Description
Constraint	constraint	Constraint to add, constraint may not be null
System.String	name	The unique name for this constraint. If the name is NullOrWhiteSpace, a base64 index will be generated for this constraint. If NameHandling is false, the passed name is discarded and a base64 index is used instead.

AddConstraint(OperatorConstraint)

Adds operatorConstraint to the OperatorConstraints in the model.

Declaration

public void AddConstraint(OperatorConstraint operatorConstraint)

Parameters

Type	Name	Description
OperatorConstraint	operatorConstraint	The OperatorConstraint (Not, Or, Where).

AddConstraint(String, Double, Double, Expression)

Adds a new Constraint to this model instance if it is consistent.

Declaration

public Constraint AddConstraint(string name, double lowerBound, double upperBound, Expression expression)

Parameters

Type	Name	Description
System.String	name	The unique name for this constraint. If the name is NullOrWhiteSpace, a base64 index will be generated for this constraint. If NameHandling is false, the passed name is discarded and a base64 index is used instead.
System.Double	lowerBound	Lower bound (left hand side) of the new constraint.
System.Double	upperBound	Upper bound (right hand side) of the new constraint.
Expression	expression	Expression of the new constraint.

Returns

Type	Description
Constraint	The newly created Constraint.

AddConstraintIfRelevant(Constraint)

Adds the given constraint if IsRelevant(Constraint).

Declaration

public bool AddConstraintIfRelevant(Constraint constraint)

Parameters

Type	Name	Description
Constraint	constraint	The constraint to add.

Returns

Type	Description
System.Boolean	true, if the constraint was added.

AddConstraintIfRelevant(Constraint, String)

Adds the given constraint if IsRelevant(Constraint).

Declaration

public bool AddConstraintIfRelevant(Constraint constraint, string name)

Parameters

Type	Name	Description
Constraint	constraint	The constraint to add.
System.String	name	The name for the constraint. If null, a new name will be generated.

Returns

Type	Description
System.Boolean	true, if the constraint was added.

AddConstraints(IEnumerable<Constraint>)

Adds a set of constraint to this model instance if it is consistent.

Declaration

public void AddConstraints(IEnumerable<Constraint> constraints)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<Constraint>	constraints	Set of constraints to add.

AddObjective(Objective, String)

Adds another objective to this model.

Make sure to only use multiple objectives, if the SolverBase that you use implements the interface OPTANO.Modeling.Optimization.Solver.Interfaces.ICanManipulateANativeSolver. Other solvers only support a single objective.

Declaration

public void AddObjective(Objective objective, string name = null)

Parameters

Type	Name	Description
Objective	objective	The objective.
System.String	name	The name for the objective or null, if the current Name should be used.

Exceptions

Type	Condition
System.ArgumentNullException	objective mustn't be null.
System.ArgumentException	objective.Expression mustn't be null.
System.InvalidOperationException	The objective name must be unique.

AddRelevantConstraints(IEnumerable<Constraint>)

Adds all constraints that fulfill IsRelevant(Constraint).

Declaration

public int AddRelevantConstraints(IEnumerable<Constraint> constraints)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<Constraint>	constraints

Returns

Type	Description
System.Int32	The number of added, relevant constraints.

AddSOS(Dictionary<Variable, Double>, SOSType)

Adds an SOS Constraint of the given SOSType.

Declaration

public void AddSOS(Dictionary<Variable, double> variables, SOSType type)

Parameters

Type	Name	Description
System.Collections.Generic.Dictionary<Variable, System.Double>	variables	The variables with a weight in the SOS for every variable. The weight is used to determine the ordering of variables in S2. Variables in the SOS 2 will be ordered ascending by weight. Important: Some Solvers might interprete a weight of 0 differently than others. Make sure to only assign positive, distinct weights.
SOSType	type	The SOS type.

AddSOS1(Dictionary<Variable, Double>)

Adds an SOS1 constraint. At most one variable in this set may have a value > 0.

Declaration

public void AddSOS1(Dictionary<Variable, double> variables)

Parameters

Type	Name	Description
System.Collections.Generic.Dictionary<Variable, System.Double>	variables	The variables with a weight factor for every variable in the SOS. Important: Some Solvers might interprete a weight of 0 differently than others. Make sure to only assign positive, distinct weights.

AddSOS2(Dictionary<Variable, Double>)

Adds an SOS2 constraint. The variables in this set will be ordered ascending by the given weight. At most 2 directly ascending variables in this set may have a value > 0.

Declaration

public void AddSOS2(Dictionary<Variable, double> variables)

Parameters

Type	Name	Description
System.Collections.Generic.Dictionary<Variable, System.Double>	variables	The variables with a weight factor for every variable in the SOS. Variables in the SOS 2 will be ordered ascending by weight. Important: Some Solvers might interprete a weight of 0 differently than others. Make sure to only assign positive, distinct weights.

AddSOS3(Dictionary<Variable, Double>)

Adds an SOS3 constraint. Alle variables need to be Binary. Exactly one of the variables in this set needs to be > 0.

Declaration

public void AddSOS3(Dictionary<Variable, double> variables)

Parameters

Type	Name	Description
System.Collections.Generic.Dictionary<Variable, System.Double>	variables	The variables with a weight factor for every variable in the SOS. Important: Some Solvers might interprete a weight of 0 differently than others. Make sure to only assign positive, distinct weights.

AddVariable(Variable)

Adds variable to this model instance if it is consistent.

Declaration

public void AddVariable(Variable variable)

Parameters

Type	Name	Description
Variable	variable	Variable to add.

AddVariables(IEnumerable<Variable>)

Adds a set of variables to this model instance if it is consistent.

Declaration

public void AddVariables(IEnumerable<Variable> variables)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<Variable>	variables	Set of variables to add.

Ceil(Expression)

Returns an Expression object respresenting the ceil roundoff of the specified expression.

Declaration

public static Expression Ceil(Expression expression)

Parameters

Type	Name	Description
Expression	expression	The expression.

Returns

Type	Description
Expression	An expression that represents the ceil roundoff.

Clear()

Removes all variables, constraints, objectives and scenarios from this model instance.

Declaration

public void Clear()

ContainsConstraint(String)

Contains this model instance a constraint named name?

Declaration

public bool ContainsConstraint(string name)

Parameters

Type	Name	Description
System.String	name	Name of the constraint to search for.

Returns

Type	Description
System.Boolean	true, if the model contains a constraint with the given name. false, else.

ContainsVariable(String)

Contains this model instance a variable named name?

Declaration

public bool ContainsVariable(string name)

Parameters

Type	Name	Description
System.String	name	Name of the variable to search for.

Returns

Type	Description
System.Boolean	true, if the model contains a variable with the given name. false, else.

DeepClone()

Creates a deep clone of this model by serializing and deserializing it.

Declaration

public Model DeepClone()

Returns

Type	Description
Model	The cloned Model.

DenseOrderIndexForPrioLevel(Int32)

Gets the position of the given priority level in the sorted list of all priority levels (by optimization order), or 0 if the level is not found.

Declaration

public int DenseOrderIndexForPrioLevel(int prioLevel)

Parameters

Type	Name	Description
System.Int32	prioLevel	The priority level.

Returns

Type	Description
System.Int32	The position-index of the priority level during the (multi-objective) optimization.

Floor(Expression)

Returns an Expression object respresenting the floor roundoff of the specified expression.

Declaration

public static Expression Floor(Expression expression)

Parameters

Type	Name	Description
Expression	expression	The expression.

Returns

Type	Description
Expression	An expression that represents the floor roundoff.

GetBranchingPriority(String)

The get branching priority.

Declaration

public int? GetBranchingPriority(string variableName)

Parameters

Type	Name	Description
System.String	variableName	The variable name.

Returns

Type	Description
System.Nullable<System.Int32>	The branching priority. If no priority is specified, 0 is returned.

Exceptions

Type	Condition
System.ArgumentException	Exception is thrown if the model does not know a variable with name variableName.

GetConstraint(String)

Returns the constraint named name, or null if this model instance contains no such constraint.

Declaration

public Constraint GetConstraint(string name)

Parameters

Type	Name	Description
System.String	name	Name of the constraint to search for.

Returns

Type	Description
Constraint	The specified Constraint

GetObjective(String)

Gets the Objective with name name

Declaration

public Objective GetObjective(string name)

Parameters

Type	Name	Description
System.String	name	The objective name. This can either be the Name that was used for the Objective when it was added to the Model, OR the base64-name that was generated by the OPTANO.Modeling Framework.

Returns

Type	Description
Objective	The Objective.

Exceptions

Type	Condition
System.ArgumentException	name mustn't be null or whitespace.

GetPrioLevelByDenseOrderIndex(Int32)

Gets the n-th priority level, when sorted in optimization order. Returns 0, if zeroBasedIndex >= ObjectiveStagesCount.

Declaration

public int GetPrioLevelByDenseOrderIndex(int zeroBasedIndex)

Parameters

Type	Name	Description
System.Int32	zeroBasedIndex	The index n (zero-based).

Returns

Type	Description
System.Int32	The n-th priority level.

GetVariable(String)

Returns the variable named name, or null if this model instance contains no such variable.

Declaration

public Variable GetVariable(string name)

Parameters

Type	Name	Description
System.String	name	Name of the variable to search for.

Returns

Type	Description
Variable	The variable with Name equal to name

GetVariableNameToLongNameMapping()

Declaration

public Dictionary<string, string> GetVariableNameToLongNameMapping()

Returns

Type	Description
System.Collections.Generic.Dictionary<System.String, System.String>

Max(IEnumerable<Expression>, Double)

Returns an Expression object representing the maximum of the specified expresssions.

Declaration

public static Expression Max(IEnumerable<Expression> expressions, double bigM)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<Expression>	expressions	The expressions.
System.Double	bigM	Large number, only used if the bounds of the variables of the expressions are non-finite

Returns

Type	Description
Expression	An expression that represents the maximum of all given expressions.

Min(IEnumerable<Expression>, Double)

Returns an Expression object respresenting the minimum of the specified expressions.

Declaration

public static Expression Min(IEnumerable<Expression> expressions, double bigM)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<Expression>	expressions	The expressions.
System.Double	bigM	Large number, only used if the bounds of the variables of the expressions are non-finite

Returns

Type	Description
Expression	An expression that represents the minimum of all given expressions.

Read(Stream, FileType)

Reads the specified file in the specified format and adds the content to the current model. Note that variable collections will be not restored. All variables will be UnhandledVariables instead.

Declaration

public void Read(Stream filestream, FileType fileType = FileType.MPS)

Parameters

Type	Name	Description
System.IO.Stream	filestream	The filestream.
FileType	fileType	The file type (LP or MPS).

RemoveConstraint(String)

Removes the Constraint or OperatorConstraint named name from this model instance, or does nothing if this model instance contains no such constraint.

Declaration

public void RemoveConstraint(string name)

Parameters

Type	Name	Description
System.String	name	Name of the constraint to remove.

RemoveConstraints(IEnumerable<String>)

Removes a set of constraints from this model instance.

Declaration

public void RemoveConstraints(IEnumerable<string> names)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<System.String>	names	Names of the constraints to remove.

RemoveObjective(Objective)

Removes the given objective.

Declaration

public void RemoveObjective(Objective objective)

Parameters

Type	Name	Description
Objective	objective	The objective to remove.

Exceptions

Type	Condition
System.ArgumentException	objective mustn't be null.

RemoveObjective(String)

Removes the Objective with name name

Declaration

public void RemoveObjective(string name)

Parameters

Type	Name	Description
System.String	name	The objective name.

Exceptions

Type	Condition
System.ArgumentException	name mustn't be null or whitespace.

RemoveVariable(String)

Removes the variable named name from this model instance, or does nothing if this model instance contains no such variable.

Declaration

public void RemoveVariable(string name)

Parameters

Type	Name	Description
System.String	name	Name of the variable to remove.

RemoveVariables(IEnumerable<String>)

Removes a set of variables from this model instance.

Declaration

public void RemoveVariables(IEnumerable<string> names)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<System.String>	names	Names of the variables to remove.

SetBranchingPriority(String, Nullable<Int32>)

Sets the branching priority for the given variable.

Declaration

public void SetBranchingPriority(string variableName, int? priority)

Parameters

Type	Name	Description
System.String	variableName	The variable name.
System.Nullable<System.Int32>	priority	The branching priority. Priority must be greater or equal than 0.

UpdateVariablesFromModelContent(Dictionary<Variable, Double>)

Collects variables from Constraints (etc.) and adds them to the Variables. This is triggered automatically during Solve(Model, Dictionary<Variable, Double>), when Lazy is active.

Declaration

public void UpdateVariablesFromModelContent(Dictionary<Variable, double> variableValues = null)

Parameters

Type	Name	Description
System.Collections.Generic.Dictionary<Variable, System.Double>	variableValues	Optional start values.

Write(Stream, FileType)

Writes the model to the specified filestream.

Declaration

public void Write(Stream filestream, FileType fileType)

Parameters

Type	Name	Description
System.IO.Stream	filestream	The filestream.
FileType	fileType	Type of the file.

Extension Methods

ReflectionHelper.GetFieldValue(Object, String)

ReflectionHelper.SetFieldValue(Object, String, Object)

ExtensionMethods.Clone<T>(T)

ExtensionMethods.ThrowIfArgumentIsNull<T>(T, String)