org.tribuo.common.tree

Class TreeModel<T extends Output<T>>

java.lang.Object

org.tribuo.Model<T>

org.tribuo.SparseModel<T>

org.tribuo.common.tree.TreeModel<T>

All Implemented Interfaces:

com.oracle.labs.mlrg.olcut.provenance.Provenancable<ModelProvenance>, Serializable

Direct Known Subclasses:

IndependentRegressionTreeModel

public class TreeModel<T extends Output<T>>
extends SparseModel<T>

A Model wrapped around a decision tree root Node.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.tribuo.Model

ALL_OUTPUTS, BIAS_FEATURE, featureIDMap, generatesProbabilities, name, outputIDInfo, provenance, provenanceOutput

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TreeModel(String name, ModelProvenance description, ImmutableFeatureMap featureIDMap, ImmutableOutputInfo<T> outputIDInfo, boolean generatesProbabilities, Map<String,List<String>> activeFeatures) Constructs a trained decision tree model.

Method Summary

Modifier and Type	Method and Description
protected static <T extends Output<T>> int	computeDepth(int initialDepth, Node<T> root)
protected TreeModel<T>	copy(String newName, ModelProvenance newProvenance) Copies a model, replacing it's provenance and name with the supplied values.
int	getDepth() Probes the tree to find the depth.
Optional<Excuse<T>>	getExcuse(Example<T> example) Generates an excuse for an example.
Set<String>	getFeatures() Returns the set of features which are split on in this tree.
Map<String,List<com.oracle.labs.mlrg.olcut.util.Pair<String,Double>>>	getTopFeatures(int n) Gets the top n features associated with this model.
Prediction<T>	predict(Example<T> example) Uses the model to predict the output for a single example.
String	toString()

Methods inherited from class org.tribuo.SparseModel

copy, getActiveFeatures

Methods inherited from class org.tribuo.Model

generatesProbabilities, getExcuses, getFeatureIDMap, getName, getOutputIDInfo, getProvenance, innerPredict, predict, predict, setName, validate

Methods inherited from class java.lang.Object

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

Constructor Detail

TreeModel

protected TreeModel(String name,
                    ModelProvenance description,
                    ImmutableFeatureMap featureIDMap,
                    ImmutableOutputInfo<T> outputIDInfo,
                    boolean generatesProbabilities,
                    Map<String,List<String>> activeFeatures)

Constructs a trained decision tree model.

Only used when the tree has multiple roots, should only be called from subclasses when *all* other methods are overridden.

Parameters:

name - The model name.

description - The model provenance.

featureIDMap - The feature id map.

outputIDInfo - The output info.

generatesProbabilities - Does this model emit probabilities.

activeFeatures - The active feature set of the model.

Method Detail

getDepth

public int getDepth()

Probes the tree to find the depth.

Returns:

The depth of the tree.

computeDepth

protected static <T extends Output<T>> int computeDepth(int initialDepth,
                                                        Node<T> root)

predict

public Prediction<T> predict(Example<T> example)

Description copied from class: Model

Uses the model to predict the output for a single example.

predict does not mutate the example.

Throws IllegalArgumentException if the example has no features or no feature overlap with the model.

Specified by:

predict in class Model<T extends Output<T>>

Parameters:

example - the example to predict.

Returns:

the result of the prediction.

getTopFeatures

public Map<String,List<com.oracle.labs.mlrg.olcut.util.Pair<String,Double>>> getTopFeatures(int n)

Description copied from class: Model

Gets the top n features associated with this model.

If the model does not produce per output feature lists, it returns a map with a single element with key Model.ALL_OUTPUTS.

If the model cannot describe it's top features then it returns Collections.emptyMap().

Specified by:

getTopFeatures in class Model<T extends Output<T>>

Parameters:

n - the number of features to return. If this value is less than 0, all features should be returned for each class, unless the model cannot score it's features.

Returns:

a map from string outputs to an ordered list of pairs of feature names and weights associated with that feature in the model

getExcuse

public Optional<Excuse<T>> getExcuse(Example<T> example)

Description copied from class: Model

Generates an excuse for an example.

This attempts to explain a classification result. Generating an excuse may be quite an expensive operation.

This excuse either contains per class information or an entry with key Model.ALL_OUTPUTS.

The optional is empty if the model does not provide excuses.

Specified by:

getExcuse in class Model<T extends Output<T>>

Parameters:

example - The input example.

Returns:

An optional excuse object. The optional is empty if this model does not provide excuses.

copy

protected TreeModel<T> copy(String newName,
                            ModelProvenance newProvenance)

Description copied from class: Model

Copies a model, replacing it's provenance and name with the supplied values.

Used to provide the provenance removal functionality.

Specified by:

copy in class Model<T extends Output<T>>

Parameters:

newName - The new name.

newProvenance - The new provenance.

Returns:

A copy of the model.

getFeatures

public Set<String> getFeatures()

Returns the set of features which are split on in this tree.

Returns:

The feature names used by this tree.

toString

public String toString()

Overrides:

toString in class Model<T extends Output<T>>