Package org.apache.lucene.classification

Class KNearestFuzzyClassifier

java.lang.Object

org.apache.lucene.classification.KNearestFuzzyClassifier

All Implemented Interfaces:

Classifier<BytesRef>

public class KNearestFuzzyClassifier
extends Object
implements Classifier<BytesRef>

A k-Nearest Neighbor classifier based on NearestFuzzyQuery.

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

Constructor Summary

Constructors

Constructor	Description
KNearestFuzzyClassifier(IndexReader indexReader, Similarity similarity, Analyzer analyzer, Query query, int k, String classFieldName, String... textFieldNames)	Creates a KNearestFuzzyClassifier.

Method Summary

Modifier and Type	Method	Description
ClassificationResult<BytesRef>	assignClass(String text)	Assign a class (with score) to the given text String
List<ClassificationResult<BytesRef>>	getClasses(String text)	Get all the classes (sorted by score, descending) assigned to the given text String.
List<ClassificationResult<BytesRef>>	getClasses(String text, int max)	Get the first max classes (sorted by score, descending) assigned to the given text String.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

KNearestFuzzyClassifier

public KNearestFuzzyClassifier(IndexReader indexReader,
 Similarity similarity,
 Analyzer analyzer,
 Query query,
 int k,
 String classFieldName,
 String... textFieldNames)

Creates a KNearestFuzzyClassifier.

Parameters:

indexReader - the reader on the index to be used for classification

similarity - the Similarity to be used by the underlying IndexSearcher or null (defaults to BM25Similarity)

analyzer - an Analyzer used to analyze unseen text

query - a Query to eventually filter the docs used for training the classifier, or null if all the indexed docs should be used

k - the no. of docs to select in the MLT results to find the nearest neighbor

classFieldName - the name of the field used as the output for the classifier

textFieldNames - the name of the fields used as the inputs for the classifier, they can contain boosting indication e.g. title^10

Method Details

assignClass

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

Description copied from interface: Classifier

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.

getClasses

public List<ClassificationResult<BytesRef>> getClasses(String text)
                                                throws IOException

Description copied from interface: Classifier

Get all the classes (sorted by score, descending) assigned to the given text String.

Specified by:

getClasses in interface Classifier<BytesRef>

Parameters:

text - a String containing text to be classified

Returns:

the whole list of ClassificationResult, the classes and scores. Returns null if the classifier can't make lists.

Throws:

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

getClasses

public List<ClassificationResult<BytesRef>> getClasses(String text,
 int max)
                                                throws IOException

Description copied from interface: Classifier

Get the first max classes (sorted by score, descending) assigned to the given text String.

Specified by:

getClasses in interface Classifier<BytesRef>

Parameters:

text - a String containing text to be classified

max - the number of return list elements

Returns:

the whole list of ClassificationResult, the classes and scores. Cut for "max" number of elements. Returns null if the classifier can't make lists.

Throws:

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

toString

public String toString()

Overrides:

toString in class Object