jsat.classifiers.trees

Class DecisionTree.Node

java.lang.Object

jsat.classifiers.trees.TreeNodeVisitor

jsat.classifiers.trees.DecisionTree.Node

All Implemented Interfaces:

Serializable, Cloneable

Enclosing class:

DecisionTree

protected static class DecisionTree.Node
extends TreeNodeVisitor

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected DecisionTree.Node[]	paths
protected DecisionStump	stump

Constructor Summary

Constructors

Constructor and Description
Node(DecisionStump stump)

Method Summary

Modifier and Type	Method and Description
int	childrenCount() Returns the number of children this node of the tree has, and may return a non zero value even if the node is a leaf
DecisionTree.Node	clone()
void	disablePath(int child) Disables the selected path to the specified child from the current node.
Collection<Integer>	featuresUsed() Returns a collection of the indices of the features used by this node in the tree to make its decision about what branch to use next.
TreeNodeVisitor	getChild(int child) Returns the node for the specific child, or null if the child index was not valid
int	getPath(DataPoint dp) Returns the path down the tree the given data point would have taken, or -1 if this node was a leaf node OR if a missing value prevent traversal down the path
double	getPathWeight(int path) Returns the relative weight of each path, which should be an indication of how much of the training data went down each path.
boolean	isLeaf() Returns true if the node is a leaf, meaning it has no valid paths to any children
boolean	isPathDisabled(int child) Returns true if the path to the specified child is disabled, meaning it can not be traveled to.
CategoricalResults	localClassify(DataPoint dp) Returns the classification result that would have been obtained if the current node was a leaf node.
double	localRegress(DataPoint dp) Returns the regression result that would have been obtained if the current node was a leaf node.
void	setPath(int child, TreeNodeVisitor node) Optional operation! This method, if supported, will set the path so that the child is set to the given value.

Methods inherited from class jsat.classifiers.trees.TreeNodeVisitor

classify, regress

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

stump

protected final DecisionStump stump

paths

protected DecisionTree.Node[] paths

Constructor Detail

Node

public Node(DecisionStump stump)

Method Detail

getPathWeight

public double getPathWeight(int path)

Description copied from class: TreeNodeVisitor

Returns the relative weight of each path, which should be an indication of how much of the training data went down each path. By default, returns 1.0/TreeNodeVisitor.childrenCount(). The result should sum to one

Overrides:

getPathWeight in class TreeNodeVisitor

Parameters:

path - the path to select

Returns:

the fraction of data estimated to travel the specified path, with respect to data that reaches this node.

isLeaf

public boolean isLeaf()

Description copied from class: TreeNodeVisitor

Returns true if the node is a leaf, meaning it has no valid paths to any children

Specified by:

isLeaf in class TreeNodeVisitor

Returns:

true if the node is purely a leaf node

childrenCount

public int childrenCount()

Description copied from class: TreeNodeVisitor

Returns the number of children this node of the tree has, and may return a non zero value even if the node is a leaf

Specified by:

childrenCount in class TreeNodeVisitor

Returns:

the number of children this node has

localClassify

public CategoricalResults localClassify(DataPoint dp)

Description copied from class: TreeNodeVisitor

Returns the classification result that would have been obtained if the current node was a leaf node.

Overrides:

localClassify in class TreeNodeVisitor

Parameters:

dp - the data point to localClassify

Returns:

the classification result

localRegress

public double localRegress(DataPoint dp)

Description copied from class: TreeNodeVisitor

Returns the regression result that would have been obtained if the current node was a leaf node.

Overrides:

localRegress in class TreeNodeVisitor

Parameters:

dp - the data point to regress

Returns:

the classification result

clone

public DecisionTree.Node clone()

Specified by:

clone in class TreeNodeVisitor

getChild

public TreeNodeVisitor getChild(int child)

Description copied from class: TreeNodeVisitor

Returns the node for the specific child, or null if the child index was not valid

Specified by:

getChild in class TreeNodeVisitor

Parameters:

child - the index of the child node to obtain

Returns:

the node for the child

setPath

public void setPath(int child,
                    TreeNodeVisitor node)

Description copied from class: TreeNodeVisitor

Optional operation!
This method, if supported, will set the path so that the child is set to the given value.
The implementation may choose to throw an exception if the NodeVisitor is not of the same implementing class.

Overrides:

setPath in class TreeNodeVisitor

Parameters:

child - the child path

node - the node to make the child

disablePath

public void disablePath(int child)

Description copied from class: TreeNodeVisitor

Disables the selected path to the specified child from the current node. All child indices will not be effected by this operation.

Specified by:

disablePath in class TreeNodeVisitor

Parameters:

child - the index of the child to disable the path too

getPath

public int getPath(DataPoint dp)

Description copied from class: TreeNodeVisitor

Returns the path down the tree the given data point would have taken, or -1 if this node was a leaf node OR if a missing value prevent traversal down the path

Specified by:

getPath in class TreeNodeVisitor

Parameters:

dp - the data point to send down the tree

Returns:

the path that would be taken

isPathDisabled

public boolean isPathDisabled(int child)

Description copied from class: TreeNodeVisitor

Returns true if the path to the specified child is disabled, meaning it can not be traveled to. It will also return true for an invalid child path, since a non existent node can not be reached.

Specified by:

isPathDisabled in class TreeNodeVisitor

Parameters:

child - the child index to check the path for

Returns:

true if the path is unavailable, false if the path is good.

featuresUsed

public Collection<Integer> featuresUsed()

Description copied from class: TreeNodeVisitor

Returns a collection of the indices of the features used by this node in the tree to make its decision about what branch to use next. Numeric features start from zero, and categorical features start from the number of numeric features.

Specified by:

featuresUsed in class TreeNodeVisitor

Returns:

the integers indicating which features were used for this node in the tree.