Class Variable

Represents a discrete or continuous random variable.

Inheritance

System.Object

Variable

Implements

System.ComponentModel.INotifyPropertyChanged

System.IComparable<Variable>

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

Namespace: BayesServer

Assembly: BayesServer.dll

Syntax

public sealed class Variable : INotifyPropertyChanged, IComparable<Variable>

Remarks

Note that variable names must be unique per network, and are case sensitive.

A Node in a Bayesian network can contain one or more variables.

Although a discrete variable can contain a different number of states, a continuous variable always contains a single state.

Constructors

Variable()

Initializes a new instance of the Variable class, with VariableValueType discrete and zero states.

Declaration

public Variable()

Variable(String)

Initializes a new instance of the Variable class, with VariableValueType discrete, zero states, and the specified name.

Declaration

public Variable(string name)

Parameters

Type	Name	Description
System.String	name	The name of the variable. Can be null.

Variable(String, State[])

Initializes a new instance of the Variable class, with VariableValueType discrete and the specified name and adds the states specified in states.

Declaration

public Variable(string name, params State[] states)

Parameters

Type	Name	Description
System.String	name	The name of the node and variable.
State[]	states	The states to add to the associated Variable.

Exceptions

Type	Condition
System.ArgumentNullException	Raised when states is null.
System.ArgumentException	Raised when the names in states are not unique, or are null or empty.

Variable(String, VariableValueType)

Initializes a new instance of the Variable class with the specified name and value type. If discrete, no states are added.

Declaration

public Variable(string name, VariableValueType valueType)

Parameters

Type	Name	Description
System.String	name	The name of the variable. Can be null.
VariableValueType	valueType	The value type, e.g. continuous or discrete.

Variable(String, VariableValueType, VariableKind)

Initializes a new instance of the Variable class with the specified name, kind and value type. If discrete, no states are added.

Declaration

public Variable(string name, VariableValueType valueType, VariableKind kind)

Parameters

Type	Name	Description
System.String	name	The name of the variable. Can be null.
VariableValueType	valueType	The value type, e.g. continuous or discrete.
VariableKind	kind	The kind of Variable, e.g. Probability, Decision or Utility.

Variable(String, Int32)

Initializes a new instance of the Variable class, with VariableValueType discrete and the specified name and adds the number of states specified in states.

Declaration

public Variable(string name, int states)

Parameters

Type	Name	Description
System.String	name	The name to give the Variable, which can be null or empty.
System.Int32	states	The number of states to add to the Variable. States will be given default names.

Exceptions

Type	Condition
System.ArgumentOutOfRangeException	Raised when the states parameter is less than zero.

Variable(String, String[])

Initializes a new instance of the Variable class, with VariableValueType discrete and the specified name and adds the states specified in states.

Declaration

public Variable(string name, string[] states)

Parameters

Type	Name	Description
System.String	name	The name of the node and variable.
System.String[]	states	The states to add to the associated Variable, specified by their names.

Exceptions

Type	Condition
System.ArgumentNullException	Raised when states is null.
System.ArgumentException	Raised when the names in states are not unique, or are null or empty.

Properties

CustomProperties

Gets custom properties associated with this instance.

Declaration

public CustomPropertyCollection CustomProperties { get; }

Property Value

Type	Description
CustomPropertyCollection

Remarks

Custom properties allow storage of custom information, which will be saved with the network.

Description

An optional description for the variable.

Declaration

public string Description { get; set; }

Property Value

Type	Description
System.String

ExpressionAlias

Gets or sets a c-style name for a variable that can be used as an alias in expressions.

Declaration

public string ExpressionAlias { get; set; }

Property Value

Type	Description
System.String

Function

Gets or sets an expression, which is evaluated during a query, and can be based on other queries and expressions.

Declaration

public IQueryExpression Function { get; set; }

Property Value

Type	Description
IQueryExpression

Index

The Index of this instance in the collection of variables belonging to a network, or -1 if the variable does not belong to a node and hence a network.

Declaration

public int Index { get; }

Property Value

Type	Description
System.Int32

Kind

Gets the kind of variable, such as Probability, Decision, Utility or Function.

Declaration

public VariableKind Kind { get; }

Property Value

Type	Description
VariableKind

Name

Gets or sets the name of the variable.

Declaration

public string Name { get; set; }

Property Value

Type	Description
System.String

Remarks

When a variable is added to a network, its name must be unique. Comparisons are case sensitive.

Node

Gets the Node this instance belongs to, if any.

Declaration

public Node Node { get; }

Property Value

Type	Description
Node	The node the instance belongs to, if any.

States

Returns the collection of states belonging to the variable.

Declaration

[TypeConverter(typeof(ExpandableObjectConverter))]
public StateCollection States { get; }

Property Value

Type	Description
StateCollection

Remarks

Continuous variables always have a single state.

See Also

State

StateValueType

Gets or sets the type of value that states belonging to this variable can represent. For example an interval.

Declaration

public StateValueType StateValueType { get; set; }

Property Value

Type	Description
StateValueType

ValueType

Gets the variable's value type, e.g. continuous or discrete.

Declaration

public VariableValueType ValueType { get; }

Property Value

Type	Description
VariableValueType	The variable's value type.

Methods

CompareTo(Variable)

Declaration

public int CompareTo(Variable other)

Parameters

Type	Name	Description
Variable	other

Returns

Type	Description
System.Int32

Copy()

Copies this instance.

Declaration

public Variable Copy()

Returns

Type	Description
Variable	A new Variable instance.

FindStateByValue(Object)

Finds a state based on a state value. E.g. finds the state who's interval contains the supplied value, or who's integer state value matches the supplied integer.

Declaration

public State FindStateByValue(object value)

Parameters

Type	Name	Description
System.Object	value	The value to test against state values. Type will depend on StateValueType. e.g. pass a double if the state value type is a double interval.

Returns

Type	Description
State	The matching state or null.

ToString()

Returns the name of the variable, or an empty string if the name is null.

Declaration

public override string ToString()

Returns

Type	Description
System.String	A System.String containing the name of the variable which is empty if the name is null.

Overrides

System.Object.ToString()

Events

PropertyChanged

Declaration

public event PropertyChangedEventHandler PropertyChanged

Event Type

Type	Description
System.ComponentModel.PropertyChangedEventHandler

Implements

System.ComponentModel.INotifyPropertyChanged

System.IComparable<T>