Class VariableCollection

This is essentially a helper class that allows you to model your Variables more intuitively. It groups Variables with the same meaning. In a mathematical model a VariableCollection is represented by a single symbol (like x); a variable by a symbol with indices (like x_{i,j}). Some (optional) generators are used to calculate parameters for each of the VariableCollection's variable:

• DebugNameGenerator

• LowerBoundGenerator

• UpperBoundGenerator

• BranchingPriorityGenerator

Inheritance

System.Object

VariableCollection

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

[Serializable]
public class VariableCollection : IInternalVariableCollection, IVariableCollection

Constructors

VariableCollection(Model, String, VariableCollection.DebugNameGenerator, VariableCollection.BoundGenerator, VariableCollection.BoundGenerator, VariableCollection.VariableTypeGeneratorDelegate, VariableCollection.BranchingPriorityGenerator, VariableCollection.BranchingDirectionGenerator, IEnumerable[])

Initializes a new instance of the VariableCollection class.

Declaration

public VariableCollection(Model model, string name = "", VariableCollection.DebugNameGenerator debugNameGenerator = null, VariableCollection.BoundGenerator lowerBoundGenerator = null, VariableCollection.BoundGenerator upperBoundGenerator = null, VariableCollection.VariableTypeGeneratorDelegate variableTypeGenerator = null, VariableCollection.BranchingPriorityGenerator branchingPriorityGenerator = null, VariableCollection.BranchingDirectionGenerator branchingDirectionGenerator = null, params IEnumerable[] sets)

Parameters

Type	Name	Description
Model	model	The model.
System.String	name	The name for this variable collection. It must be unique among all VariableCollections that are used in the given model. If name IsNullOrWhiteSpace, a base64 index will be generated automatically.
VariableCollection.DebugNameGenerator	debugNameGenerator	A delegate that takes an object[] as input and produces a System.Text.StringBuilder as output. The generator will be used when NameHandling is true. The string that is produced by the StringBuilder will be prepended to the unique variable name. The objective is to make the generated Model more readable, especially when trying to fix bugs. By default, the NameHandling is set to false in order to reduce the amount of RAM required to store variable names.
VariableCollection.BoundGenerator	lowerBoundGenerator	A generator function for the lower bound. If null is passed, 0 will be used as default lower bound for every variable.
VariableCollection.BoundGenerator	upperBoundGenerator	A generator function for the upper bound. If null is passed, double.PositiveInfinity will be used as default upper bound for every non-binary variable. For variables, 1 will be used as upper bound.
VariableCollection.VariableTypeGeneratorDelegate	variableTypeGenerator
VariableCollection.BranchingPriorityGenerator	branchingPriorityGenerator	The branching priority generator. Non-null result of the generator function will be passed as branching priority to the SolverBase, if different priorities are supported.
VariableCollection.BranchingDirectionGenerator	branchingDirectionGenerator	The branching direction generator.
System.Collections.IEnumerable[]	sets	The index sets.

Fields

_branchingDirectionGenerator

The branching direction generator.

Declaration

[NonSerialized]
protected VariableCollection.BranchingDirectionGenerator _branchingDirectionGenerator

Field Value

Type	Description
VariableCollection.BranchingDirectionGenerator

_branchingPriorityGenerator

The branching priority generator.

Declaration

[NonSerialized]
protected VariableCollection.BranchingPriorityGenerator _branchingPriorityGenerator

Field Value

Type	Description
VariableCollection.BranchingPriorityGenerator

_name

The name.

Declaration

protected readonly string _name

Field Value

Type	Description
System.String

Properties

ExistingIndices

Gets the existing indices.

Declaration

public IEnumerable<object[]> ExistingIndices { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<System.Object[]>	The System.Collections.IEnumerable with all already known indices. I.e. all indices that have already been used to access this VariableCollection.

Implements

IVariableCollection.ExistingIndices

ExistingVariables

Gets the set of all existing (i.e. already created) variables.

Declaration

public IEnumerable<Variable> ExistingVariables { get; }

Property Value

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

IndexValidationStyle

Gets or sets the IndexValidationStyle. Changes the behavior of a VariableCollection. If set to true the VariableCollection will validate if an index belongs to the sets the VariableCollection is based on. The check is computationally expensive and should only be performed when you debug a model. If the style is changed to Heuristic, new hash sets will be generated from the current index sets. Otherwise, the hash sets will be cleared.

Declaration

public IndexValidationStyle IndexValidationStyle { get; set; }

Property Value

Type	Description
IndexValidationStyle

Implements

IVariableCollection.IndexValidationStyle

Item[Object[]]

Gets the Variable with the specified index. If the VariableCollection never was accessed with the index, a new variable will be generated.

Declaration

public Variable this[params object[] index] { get; }

Parameters

Type	Name	Description
System.Object[]	index	The index for the Variable that should be accessed.

Property Value

Type	Description
Variable	The variable for the given index

Name

Gets the name for this variable collection. It must be unique among all VariableCollections that are used in a single Model.

Declaration

public string Name { get; }

Property Value

Type	Description
System.String

Implements

IVariableCollection.Name

ValidIndices

Gets an System.Collections.Generic.IEnumerable<T> that iterates over all valid index combinations for this VariableCollection.

Declaration

public IEnumerable<object[]> ValidIndices { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<System.Object[]>	The valid indices.

Implements

IVariableCollection.ValidIndices

Variables

Gets an System.Collections.IEnumerable that contains all existing Variables in this VariableCollection. I.e. all variables that were generated when this VariableCollection was accessed with the variables index.

Declaration

public IEnumerable<Variable> Variables { get; }

Property Value

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

Implements

IVariableCollection.Variables

VariableTypeGenerator

Gets a generator delegate that takes an index as input and returns the VariableType for the respective Variable.

Declaration

public VariableCollection.VariableTypeGeneratorDelegate VariableTypeGenerator { get; }

Property Value

Type	Description
VariableCollection.VariableTypeGeneratorDelegate

Implements

IVariableCollection.VariableTypeGenerator

Methods

CreateAllVariables()

Creates all variables that can possibly be created based on the elements currently in the sets. Be aware, this might create a major bunch of variables. It is usally used for internal testing.

Declaration

public IEnumerable<Variable> CreateAllVariables()

Returns

Type	Description
System.Collections.Generic.IEnumerable<Variable>	All variables in this VariableCollection.

GetLongNameFromIndex(Object[])

If the model uses short names, the long name is generated from the given index. Else, the name of the variable for the given index is returned.

Declaration

public string GetLongNameFromIndex(object[] index)

Parameters

Type	Name	Description
System.Object[]	index	The index. If the variable for the index has not been created yet, an exception will be thrown.

Returns

Type	Description
System.String	The System.String.

Exceptions

Type	Condition
System.ArgumentException	Thrown, if the index is not yet known.

IsVariableForIndexInstanciated(Object[])

Checks if a variable was created for the given index.

Declaration

public bool IsVariableForIndexInstanciated(params object[] index)

Parameters

Type	Name	Description
System.Object[]	index	The index.

Returns

Type	Description
System.Boolean	True, if a variable was created.

Implements

IVariableCollection.IsVariableForIndexInstanciated(Object[])

SetVariableValues(IDictionary<String, Double>)

Sets the Value for each Variable in this VariableCollection to the corresponding value in the values. The matching happens by string comparison with the Name. Values will only be updated for Variables that are known to this VariableCollection. Other System.Collections.KeyValuePairs will be ignored. The same is true for Variables in this Collection, for which no matching element is contained in the values.

Declaration

public void SetVariableValues(IDictionary<string, double> values)

Parameters

Type	Name	Description
System.Collections.Generic.IDictionary<System.String, System.Double>	values	The values for the variables (e.g. coming from a Solution)

Implements

IVariableCollection.SetVariableValues(IDictionary<String, Double>)

Extension Methods

ReflectionHelper.GetFieldValue(Object, String)

ReflectionHelper.SetFieldValue(Object, String, Object)

ExtensionMethods.Clone<T>(T)

ExtensionMethods.ThrowIfArgumentIsNull<T>(T, String)