org.apache.lucene.classification

Class KNearestNeighborClassifier

java.lang.Object

org.apache.lucene.classification.KNearestNeighborClassifier

All Implemented Interfaces:

Classifier<BytesRef>

public class KNearestNeighborClassifier
extends Object
implements Classifier<BytesRef>

A k-Nearest Neighbor classifier (see http://en.wikipedia.org/wiki/K-nearest_neighbors) based on MoreLikeThis

WARNING: This API is experimental and might change in incompatible ways in the next release.

Constructor Summary

Constructors

Constructor and Description
KNearestNeighborClassifier(int k) Create a Classifier using kNN algorithm

Method Summary

Methods

Modifier and Type	Method and Description
ClassificationResult<BytesRef>	assignClass(String text) Assign a class (with score) to the given text String
void	train(AtomicReader atomicReader, String textFieldName, String classFieldName, Analyzer analyzer) Train the classifier using the underlying Lucene index

Methods inherited from class java.lang.Object

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

Constructor Detail

KNearestNeighborClassifier

public KNearestNeighborClassifier(int k)

Create a Classifier using kNN algorithm

Parameters:

k - the number of neighbors to analyze as an int

Method Detail

assignClass

public ClassificationResult<BytesRef> assignClass(String text)
                                           throws IOException

Assign a class (with score) to the given text String

Specified by:

assignClass in interface Classifier<BytesRef>

Parameters:

text - a String containing text to be classified

Returns:

a ClassificationResult holding assigned class of type T and score

Throws:

IOException - If there is a low-level I/O error.

train

public void train(AtomicReader atomicReader,
         String textFieldName,
         String classFieldName,
         Analyzer analyzer)
           throws IOException

Train the classifier using the underlying Lucene index

Specified by:

train in interface Classifier<BytesRef>

Parameters:

atomicReader - the reader to use to access the Lucene index

textFieldName - the name of the field used to compare documents

classFieldName - the name of the field containing the class assigned to documents

analyzer - the analyzer used to tokenize / filter the unseen text

Throws:

IOException - If there is a low-level I/O error.