public class SimpleNaiveBayesClassifier extends Object implements Classifier<BytesRef>
http://en.wikipedia.org/wiki/Naive_Bayes_classifier
Modifier and Type | Field and Description |
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protected Analyzer |
analyzer
Analyzer to be used for tokenizing unseen input text |
protected String |
classFieldName
name of the field to be used as a class / category output
|
protected IndexReader |
indexReader
IndexReader used to access the Classifier 's
index |
protected IndexSearcher |
indexSearcher
IndexSearcher to run searches on the index for retrieving frequencies |
protected Query |
query
Query used to eventually filter the document set to be used to classify |
protected String[] |
textFieldNames
names of the fields to be used as input text
|
Constructor and Description |
---|
SimpleNaiveBayesClassifier(IndexReader indexReader,
Analyzer analyzer,
Query query,
String classFieldName,
String... textFieldNames)
Creates a new NaiveBayes classifier.
|
Modifier and Type | Method and Description |
---|---|
ClassificationResult<BytesRef> |
assignClass(String inputDocument)
Assign a class (with score) to the given text String
|
protected List<ClassificationResult<BytesRef>> |
assignClassNormalizedList(String inputDocument)
Calculate probabilities for all classes for a given input text
|
protected int |
countDocsWithClass()
count the number of documents in the index having at least a value for the 'class' field
|
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. |
protected ArrayList<ClassificationResult<BytesRef>> |
normClassificationResults(List<ClassificationResult<BytesRef>> assignedClasses)
Normalize the classification results based on the max score available
|
protected String[] |
tokenize(String text)
tokenize a
String on this classifier's text fields and analyzer |
protected final IndexReader indexReader
IndexReader
used to access the Classifier
's
indexprotected final String[] textFieldNames
protected final String classFieldName
protected final IndexSearcher indexSearcher
IndexSearcher
to run searches on the index for retrieving frequenciespublic SimpleNaiveBayesClassifier(IndexReader indexReader, Analyzer analyzer, Query query, String classFieldName, String... textFieldNames)
indexReader
- the reader on the index to be used for classificationanalyzer
- an Analyzer
used to analyze unseen textquery
- a Query
to eventually filter the docs used for training the classifier, or null
if all the indexed docs should be usedclassFieldName
- the name of the field used as the output for the classifier NOTE: must not be havely analyzed
as the returned class will be a token indexed for this fieldtextFieldNames
- the name of the fields used as the inputs for the classifier, NO boosting supported per fieldpublic ClassificationResult<BytesRef> assignClass(String inputDocument) throws IOException
Classifier
assignClass
in interface Classifier<BytesRef>
inputDocument
- a String containing text to be classifiedClassificationResult
holding assigned class of type T
and scoreIOException
- If there is a low-level I/O error.public List<ClassificationResult<BytesRef>> getClasses(String text) throws IOException
Classifier
getClasses
in interface Classifier<BytesRef>
text
- a String containing text to be classifiedClassificationResult
, the classes and scores. Returns null
if the classifier can't make lists.IOException
- If there is a low-level I/O error.public List<ClassificationResult<BytesRef>> getClasses(String text, int max) throws IOException
Classifier
max
classes (sorted by score, descending) assigned to the given text String.getClasses
in interface Classifier<BytesRef>
text
- a String containing text to be classifiedmax
- the number of return list elementsClassificationResult
, the classes and scores. Cut for "max" number of elements. Returns null
if the classifier can't make lists.IOException
- If there is a low-level I/O error.protected List<ClassificationResult<BytesRef>> assignClassNormalizedList(String inputDocument) throws IOException
inputDocument
- the input text as a String
List
of ClassificationResult
, one for each existing classIOException
- if assigning probabilities failsprotected int countDocsWithClass() throws IOException
IOException
- if accessing to term vectors or search failsprotected String[] tokenize(String text) throws IOException
String
on this classifier's text fields and analyzertext
- the String
representing an input text (to be classified)String
array of the resulting tokensIOException
- if tokenization failsprotected ArrayList<ClassificationResult<BytesRef>> normClassificationResults(List<ClassificationResult<BytesRef>> assignedClasses)
assignedClasses
- the list of assigned classesCopyright © 2000-2018 Apache Software Foundation. All Rights Reserved.