org.apache.lucene.classification

Interface Classifier<T>

All Known Implementing Classes:

BooleanPerceptronClassifier, CachingNaiveBayesClassifier, KNearestNeighborClassifier, SimpleNaiveBayesClassifier

public interface Classifier<T>

A classifier, see http://en.wikipedia.org/wiki/Classifier_(mathematics), which assign classes of type T

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

Method Summary

Methods

Modifier and Type	Method and Description
ClassificationResult<T>	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.
void	train(LeafReader leafReader, String[] textFieldNames, String classFieldName, Analyzer analyzer, Query query) Train the classifier using the underlying Lucene index
void	train(LeafReader leafReader, String textFieldName, String classFieldName, Analyzer analyzer) Train the classifier using the underlying Lucene index
void	train(LeafReader leafReader, String textFieldName, String classFieldName, Analyzer analyzer, Query query) Train the classifier using the underlying Lucene index

Method Detail

assignClass

ClassificationResult<T> assignClass(String text)
                                    throws IOException

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

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

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

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

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

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

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

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.

train

void train(LeafReader leafReader,
         String textFieldName,
         String classFieldName,
         Analyzer analyzer)
           throws IOException

Train the classifier using the underlying Lucene index

Parameters:

leafReader - 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.

train

void train(LeafReader leafReader,
         String textFieldName,
         String classFieldName,
         Analyzer analyzer,
         Query query)
           throws IOException

Train the classifier using the underlying Lucene index

Parameters:

leafReader - 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

query - the query to filter which documents use for training

Throws:

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

train

void train(LeafReader leafReader,
         String[] textFieldNames,
         String classFieldName,
         Analyzer analyzer,
         Query query)
           throws IOException

Train the classifier using the underlying Lucene index

Parameters:

leafReader - the reader to use to access the Lucene index

textFieldNames - the names of the fields to be 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

query - the query to filter which documents use for training

Throws:

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