Package edu.cmu.tetrad.data

Class DiscreteVariable

java.lang.Object

edu.cmu.tetrad.data.AbstractVariable

edu.cmu.tetrad.data.DiscreteVariable

All Implemented Interfaces:

Variable, Node, TetradSerializable, Serializable, Comparable<Node>

public final class DiscreteVariable
extends AbstractVariable
implements Node

Represents a discrete variable as a range of integer-valued categories 0, 1, ..., m - 1, where m is the number of categories for the variable. These integer-valued categories may be associated with categories that may be explicitly set. Categories that are not explicitly set take the are set to DataUtils.defaultCategory(i) for category i.

Instances of this class may currently be used only to represent nominal discrete variables. Support for ordinal discrete variables may be added in the future.

Like other variable classes, DiscreteVariable implements the Node interface. The purpose of this is to allow variables to serve as nodes in graphs.

The index value used to indicate missing data is -99.

Version:

$Id: $Id

Author:

josephramsey

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final int	MISSING_VALUE	This is the index in the data which represents missing data internally for this variable.

Fields inherited from class edu.cmu.tetrad.data.AbstractVariable

LAST_ID

Fields inherited from interface edu.cmu.tetrad.graph.Node

ALPHA, ALPHA_NUM, LAG

Constructor Summary

Constructors

Constructor	Description
DiscreteVariable(DiscreteVariable variable)	Copy constructor.
DiscreteVariable(String name)	Builds a discrete variable with the given name and an empty list of categories.
DiscreteVariable(String name, int numCategories)	Builds a qualitative variable with the given name and number of categories.
DiscreteVariable(String name, List<String> categories)	Builds a qualitative variable with the given name and array of possible categories.

Method Summary

Modifier and Type	Method	Description
void	addAttribute(String key, Object value)	addAttribute.
void	addPropertyChangeListener(PropertyChangeListener l)	Adds a property change listener.
boolean	checkValue(int category)	checkValue.
boolean	equals(Object o)	Tests whether this variable is equal to the given variable.
Map<String,Object>	getAllAttributes()	getAllAttributes.
Object	getAttribute(String key)	getAttribute.
List<String>	getCategories()	Getter for the field categories.
String	getCategory(int category)	getCategory.
int	getCenterX()	Getter for the field centerX.
int	getCenterY()	Getter for the field centerY.
int	getIndex(String category)	getIndex.
Object	getMissingValueMarker()	getMissingValueMarker.
NodeType	getNodeType()	Getter for the field nodeType.
NodeVariableType	getNodeVariableType()	Returns the node shape for this node.
int	getNumCategories()	getNumCategories.
boolean	getSelectionBias()	Returns the selection bias status for this node.
int	hashCode()	hashCode.
boolean	isAccommodateNewCategories()	isAccommodateNewCategories.
boolean	isCategoryNamesDisplayed()	isCategoryNamesDisplayed.
boolean	isMissingValue(Object value)	Tests whether the given value is the missing data marker.
Node	like(String name)	Creates a new node of the same type as this one with the given name.
void	removeAttribute(String key)	removeAttribute.
static DiscreteVariable	serializableInstance()	Generates a simple exemplar of this class to test serialization.
void	setCategoryNamesDisplayed(boolean categoryNamesDisplayed)	Sets whether categories for this variable should be displayed.
void	setCenter(int centerX, int centerY)	Sets the (x, y) coordinates of the center of this node.
void	setCenterX(int centerX)	Sets the x coordinate of the center of this node.
void	setCenterY(int centerY)	Sets the y coordinate of the center of this node.
void	setNodeType(NodeType nodeType)	Sets the node type for this node.
void	setNodeVariableType(NodeVariableType nodeVariableType)	Sets the type (domain, interventional status, interventional value..) for this node variable
void	setSelectionBias(boolean selectionBias)	Sets the selection bias status for this node.
String	toString()	toString.

Methods inherited from class edu.cmu.tetrad.data.AbstractVariable

checkValue, getName, setName

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface edu.cmu.tetrad.graph.Node

compareTo, getName, setName

Field Details

MISSING_VALUE

public static final int MISSING_VALUE

This is the index in the data which represents missing data internally for this variable.

See Also:

• Constant Field Values

Constructor Details

DiscreteVariable

public DiscreteVariable(String name)

Builds a discrete variable with the given name and an empty list of categories. Use this constructor if a variable is needed to represent just a list of integer categories with no categories associated with the categories.

Parameters:

name - a String object

DiscreteVariable

public DiscreteVariable(String name,
 int numCategories)

Builds a qualitative variable with the given name and number of categories. The categories have the form 'category'.

Parameters:

name - a String object

numCategories - a int

DiscreteVariable

public DiscreteVariable(String name,
 List<String> categories)

Builds a qualitative variable with the given name and array of possible categories.

Parameters:

name - The name of the variable.

categories - A String[] array of categories, where the categories[i] is the category for index i.

DiscreteVariable

public DiscreteVariable(DiscreteVariable variable)

Copy constructor.

Parameters:

variable - a DiscreteVariable object

Method Details

serializableInstance

public static DiscreteVariable serializableInstance()

Generates a simple exemplar of this class to test serialization.

Returns:

a DiscreteVariable object

getIndex

public int getIndex(String category)

getIndex.

Parameters:

category - a String object

Returns:

the index of the given String category, or -1 if the category is not a category for this variable.

getNumCategories

public int getNumCategories()

getNumCategories.

Returns:

the number of possible categories for this variable. If categories are associated, this is just the number of string categories. If no categories are associated, this is the maximum integer in the column.

getMissingValueMarker

public Object getMissingValueMarker()

getMissingValueMarker.

Specified by:

getMissingValueMarker in interface Variable

Specified by:

getMissingValueMarker in class AbstractVariable

Returns:

the missing value marker as an Integer.

getCategory

public String getCategory(int category)

getCategory.

Parameters:

category - a int

Returns:

the variable category specified by the given category.

getCategories

public List<String> getCategories()

Getter for the field categories.

Returns:

a copy of the array containing the categories for this variable. The string at index i is the category for index i.

checkValue

public boolean checkValue(int category)

checkValue.

Parameters:

category - a category to be checked

Returns:

true if the given category is legal.

isMissingValue

public boolean isMissingValue(Object value)

Tests whether the given value is the missing data marker.

Tests whether the given value is the missing data marker.

Determines whether the given value is the missing value marker.

Specified by:

isMissingValue in interface Variable

Specified by:

isMissingValue in class AbstractVariable

Parameters:

value - The object value one wants to check as a missing value.

Returns:

true iff the given object is equals to getMissingValueMarker().

isCategoryNamesDisplayed

public boolean isCategoryNamesDisplayed()

isCategoryNamesDisplayed.

Returns:

true iff categories for this variable should be displayed.

setCategoryNamesDisplayed

public void setCategoryNamesDisplayed(boolean categoryNamesDisplayed)

Sets whether categories for this variable should be displayed.

Parameters:

categoryNamesDisplayed - a boolean

hashCode

public int hashCode()

hashCode.

Specified by:

hashCode in interface Node

Overrides:

hashCode in class Object

Returns:

a int

equals

public boolean equals(Object o)

Tests whether this variable is equal to the given variable.

Specified by:

equals in interface Node

Overrides:

equals in class Object

Parameters:

o - a Object object

Returns:

true iff this variable is equal to the given variable.

getNodeType

public NodeType getNodeType()

Getter for the field nodeType.

Specified by:

getNodeType in interface Node

Returns:

a NodeType object

setNodeType

public void setNodeType(NodeType nodeType)

Sets the node type for this node.

Specified by:

setNodeType in interface Node

Parameters:

nodeType - the node type for this node.

setSelectionBias

public void setSelectionBias(boolean selectionBias)

Description copied from class: AbstractVariable

Sets the selection bias status for this node.

Specified by:

setSelectionBias in interface Node

Overrides:

setSelectionBias in class AbstractVariable

Parameters:

selectionBias - the selection bias status for this node.

getSelectionBias

public boolean getSelectionBias()

Description copied from interface: Node

Returns the selection bias status for this node.

Specified by:

getSelectionBias in interface Node

Returns:

the selection bias status for this node.

isAccommodateNewCategories

public boolean isAccommodateNewCategories()

isAccommodateNewCategories.

Returns:

a boolean

getCenterX

public int getCenterX()

Getter for the field centerX.

Specified by:

getCenterX in interface Node

Returns:

the x coordinate of the center of the node.

setCenterX

public void setCenterX(int centerX)

Sets the x coordinate of the center of this node.

Sets the x coordinate of the center of this node.

Specified by:

setCenterX in interface Node

Parameters:

centerX - This coordinate.

getCenterY

public int getCenterY()

Getter for the field centerY.

Specified by:

getCenterY in interface Node

Returns:

the y coordinate of the center of the node.

setCenterY

public void setCenterY(int centerY)

Sets the y coordinate of the center of this node.

Sets the y coordinate of the center of this node.

Specified by:

setCenterY in interface Node

Parameters:

centerY - This coordinate.

setCenter

public void setCenter(int centerX,
 int centerY)

Sets the (x, y) coordinates of the center of this node.

Sets the (x, y) coordinates of the center of this node.

Specified by:

setCenter in interface Node

Parameters:

centerX - The x coordinate.

centerY - The y coordinate.

addPropertyChangeListener

public void addPropertyChangeListener(PropertyChangeListener l)

Adds a property change listener.

Adds a property change listener.

Specified by:

addPropertyChangeListener in interface Node

Parameters:

l - This listener.

toString

public String toString()

toString.

Specified by:

toString in interface Node

Overrides:

toString in class AbstractVariable

Returns:

the name of the variable followed by its list of categories.

like

public Node like(String name)

Creates a new node of the same type as this one with the given name.

Specified by:

like in interface Node

Specified by:

like in class AbstractVariable

Parameters:

name - the name of the new node.

Returns:

the new node.

getNodeVariableType

public NodeVariableType getNodeVariableType()

Returns the node shape for this node.

Specified by:

getNodeVariableType in interface Node

Returns:

the intervention type

setNodeVariableType

public void setNodeVariableType(NodeVariableType nodeVariableType)

Sets the type (domain, interventional status, interventional value..) for this node variable

Specified by:

setNodeVariableType in interface Node

Parameters:

nodeVariableType - the type (domain, interventional status, interventional value..) for this node variable

getAllAttributes

public Map<String,Object> getAllAttributes()

getAllAttributes.

Specified by:

getAllAttributes in interface Node

Returns:

a Map object

getAttribute

public Object getAttribute(String key)

getAttribute.

Specified by:

getAttribute in interface Node

Parameters:

key - a String object

Returns:

a Object object

removeAttribute

public void removeAttribute(String key)

removeAttribute.

Specified by:

removeAttribute in interface Node

Parameters:

key - a String object

addAttribute

public void addAttribute(String key,
 Object value)

addAttribute.

Specified by:

addAttribute in interface Node

Parameters:

key - a String object

value - a Object object