Package cc.mallet.classify

Class Classifier

java.lang.Object

cc.mallet.classify.Classifier

All Implemented Interfaces:

AlphabetCarrying, java.io.Serializable

Direct Known Subclasses:

AdaBoost, AdaBoostM2, AddClassifierTokenPredictions.TokenClassifiers, BaggingClassifier, BalancedWinnow, C45, ClassifierEnsemble, ConfidencePredictingClassifier, DecisionTree, MaxEnt, MCMaxEnt, MostFrequentClassifier, NaiveBayes, PRAuxClassifier, RandomClassifier, Winnow

public abstract class Classifier
extends java.lang.Object
implements AlphabetCarrying, java.io.Serializable

Abstract parent of all Classifiers.

All classification techniques in MALLET are implemented as two classes: a trainer and a classifier. The trainer injests the training data and creates a classifier that holds the parameters set during training. The classifier applies those parameters to an Instance to produce a classification of the Instance.

A concrete classifier is required only to be able to classify an instance.

Methods for classifying an InstanceList are here. There are also methods for calculating precison, recall, and f1 from either InstanceLists (which are classified first) or an ArrayList of classifications. Similar functionality is also in Trial

A classifier holds a reference to the pipe that was used to create the Instances being classified. Most classifiers use this to make sure the Alphabets of the instances being classified are the same Alphabet objects used during training.

Alphabets are allowed to between training and classification.

See Also:

ClassifierTrainer, Instance, InstanceList, Classification, Trial, Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected Pipe	instancePipe

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Classifier()	For serialization only.
	Classifier(Pipe instancePipe)

Method Summary

Modifier and Type	Method	Description
boolean	alphabetsMatch(AlphabetCarrying object)
abstract Classification	classify(Instance instance)
Classification[]	classify(Instance[] instances)
java.util.ArrayList<Classification>	classify(InstanceList instances)
Classification	classify(java.lang.Object obj)	Pipe the object through this classifier's pipe, then classify the resulting instance.
double	getAccuracy(InstanceList ilist)
Alphabet	getAlphabet()
Alphabet[]	getAlphabets()
double	getAverageRank(InstanceList ilist)
double	getF1(InstanceList ilist, int index)
double	getF1(InstanceList ilist, Labeling labeling)
double	getF1(InstanceList ilist, java.lang.Object labelEntry)
FeatureSelection	getFeatureSelection()
Pipe	getInstancePipe()
LabelAlphabet	getLabelAlphabet()
FeatureSelection[]	getPerClassFeatureSelection()
double	getPrecision(InstanceList ilist, int index)
double	getPrecision(InstanceList ilist, Labeling labeling)
double	getPrecision(InstanceList ilist, java.lang.Object labelEntry)
double	getRecall(InstanceList ilist, int index)
double	getRecall(InstanceList ilist, Labeling labeling)
double	getRecall(InstanceList ilist, java.lang.Object labelEntry)
void	print()	Outputs human-readable description of classifier (e.g., list of weights, decision tree) to System.out
void	print(java.io.PrintWriter out)

Methods inherited from class java.lang.Object

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

Field Detail

instancePipe

protected Pipe instancePipe

Constructor Detail

Classifier

protected Classifier()

For serialization only.

Classifier

public Classifier(Pipe instancePipe)

Method Detail

getInstancePipe

public Pipe getInstancePipe()

getAlphabet

public Alphabet getAlphabet()

Specified by:

getAlphabet in interface AlphabetCarrying

getLabelAlphabet

public LabelAlphabet getLabelAlphabet()

getAlphabets

public Alphabet[] getAlphabets()

Specified by:

getAlphabets in interface AlphabetCarrying

alphabetsMatch

public boolean alphabetsMatch(AlphabetCarrying object)

classify

public java.util.ArrayList<Classification> classify(InstanceList instances)

classify

public Classification[] classify(Instance[] instances)

classify

public abstract Classification classify(Instance instance)

classify

public Classification classify(java.lang.Object obj)

Pipe the object through this classifier's pipe, then classify the resulting instance.

getFeatureSelection

public FeatureSelection getFeatureSelection()

getPerClassFeatureSelection

public FeatureSelection[] getPerClassFeatureSelection()

getAccuracy

public double getAccuracy(InstanceList ilist)

getPrecision

public double getPrecision(InstanceList ilist,
                           int index)

getPrecision

public double getPrecision(InstanceList ilist,
                           Labeling labeling)

getPrecision

public double getPrecision(InstanceList ilist,
                           java.lang.Object labelEntry)

getRecall

public double getRecall(InstanceList ilist,
                        int index)

getRecall

public double getRecall(InstanceList ilist,
                        Labeling labeling)

getRecall

public double getRecall(InstanceList ilist,
                        java.lang.Object labelEntry)

getF1

public double getF1(InstanceList ilist,
                    int index)

getF1

public double getF1(InstanceList ilist,
                    Labeling labeling)

getF1

public double getF1(InstanceList ilist,
                    java.lang.Object labelEntry)

getAverageRank

public double getAverageRank(InstanceList ilist)

print

public void print()

Outputs human-readable description of classifier (e.g., list of weights, decision tree) to System.out

print

public void print(java.io.PrintWriter out)