Class KNearestNeighborDocumentClassifier
- java.lang.Object
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- org.apache.lucene.classification.KNearestNeighborClassifier
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- org.apache.lucene.classification.document.KNearestNeighborDocumentClassifier
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- All Implemented Interfaces:
Classifier<BytesRef>
,DocumentClassifier<BytesRef>
public class KNearestNeighborDocumentClassifier extends KNearestNeighborClassifier implements DocumentClassifier<BytesRef>
A k-Nearest Neighbor Document classifier (seehttp://en.wikipedia.org/wiki/K-nearest_neighbors
) based onMoreLikeThis
.
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Field Summary
Fields Modifier and Type Field Description protected java.util.Map<java.lang.String,Analyzer>
field2analyzer
map of per field analyzers-
Fields inherited from class org.apache.lucene.classification.KNearestNeighborClassifier
classFieldName, indexSearcher, k, mlt, query, textFieldNames
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Constructor Summary
Constructors Constructor Description KNearestNeighborDocumentClassifier(IndexReader indexReader, Similarity similarity, Query query, int k, int minDocsFreq, int minTermFreq, java.lang.String classFieldName, java.util.Map<java.lang.String,Analyzer> field2analyzer, java.lang.String... textFieldNames)
Creates aKNearestNeighborClassifier
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description ClassificationResult<BytesRef>
assignClass(Document document)
Assign a class (with score) to the givenDocument
java.util.List<ClassificationResult<BytesRef>>
getClasses(Document document)
Get all the classes (sorted by score, descending) assigned to the givenDocument
.java.util.List<ClassificationResult<BytesRef>>
getClasses(Document document, int max)
Get the firstmax
classes (sorted by score, descending) assigned to the given text String.private TopDocs
knnSearch(Document document)
Returns the top k results from a More Like This query based on the input document-
Methods inherited from class org.apache.lucene.classification.KNearestNeighborClassifier
assignClass, buildListFromTopDocs, classifyFromTopDocs, getClasses, getClasses, toString
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Field Detail
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field2analyzer
protected final java.util.Map<java.lang.String,Analyzer> field2analyzer
map of per field analyzers
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Constructor Detail
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KNearestNeighborDocumentClassifier
public KNearestNeighborDocumentClassifier(IndexReader indexReader, Similarity similarity, Query query, int k, int minDocsFreq, int minTermFreq, java.lang.String classFieldName, java.util.Map<java.lang.String,Analyzer> field2analyzer, java.lang.String... textFieldNames) throws java.io.IOException
Creates aKNearestNeighborClassifier
.- Parameters:
indexReader
- the reader on the index to be used for classificationsimilarity
- theSimilarity
to be used by the underlyingIndexSearcher
ornull
(defaults toBM25Similarity
)query
- aQuery
to eventually filter the docs used for training the classifier, ornull
if all the indexed docs should be usedk
- the no. of docs to select in the MLT results to find the nearest neighborminDocsFreq
-MoreLikeThis.minDocFreq
parameterminTermFreq
-MoreLikeThis.minTermFreq
parameterclassFieldName
- the name of the field used as the output for the classifierfield2analyzer
- map with key a field name and the related {org.apache.lucene.analysis.Analyzer}textFieldNames
- the name of the fields used as the inputs for the classifier, they can contain boosting indication e.g. title^10- Throws:
java.io.IOException
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Method Detail
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assignClass
public ClassificationResult<BytesRef> assignClass(Document document) throws java.io.IOException
Description copied from interface:DocumentClassifier
Assign a class (with score) to the givenDocument
- Specified by:
assignClass
in interfaceDocumentClassifier<BytesRef>
- Parameters:
document
- aDocument
to be classified. Fields are considered features for the classification.- Returns:
- a
ClassificationResult
holding assigned class of typeT
and score - Throws:
java.io.IOException
- If there is a low-level I/O error.
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getClasses
public java.util.List<ClassificationResult<BytesRef>> getClasses(Document document) throws java.io.IOException
Description copied from interface:DocumentClassifier
Get all the classes (sorted by score, descending) assigned to the givenDocument
.- Specified by:
getClasses
in interfaceDocumentClassifier<BytesRef>
- Parameters:
document
- aDocument
to be classified. Fields are considered features for the classification.- Returns:
- the whole list of
ClassificationResult
, the classes and scores. Returnsnull
if the classifier can't make lists. - Throws:
java.io.IOException
- If there is a low-level I/O error.
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getClasses
public java.util.List<ClassificationResult<BytesRef>> getClasses(Document document, int max) throws java.io.IOException
Description copied from interface:DocumentClassifier
Get the firstmax
classes (sorted by score, descending) assigned to the given text String.- Specified by:
getClasses
in interfaceDocumentClassifier<BytesRef>
- Parameters:
document
- aDocument
to be classified. Fields are considered features for the classification.max
- the number of return list elements- Returns:
- the whole list of
ClassificationResult
, the classes and scores. Cut for "max" number of elements. Returnsnull
if the classifier can't make lists. - Throws:
java.io.IOException
- If there is a low-level I/O error.
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knnSearch
private TopDocs knnSearch(Document document) throws java.io.IOException
Returns the top k results from a More Like This query based on the input document- Parameters:
document
- the document to use for More Like This search- Returns:
- the top results for the MLT query
- Throws:
java.io.IOException
- If there is a low-level I/O error
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