# Uses of Interface
org.apache.lucene.classification.Classifier

Packages that use Classifier
Package
Description
org.apache.lucene.classification
Uses already seen data (the indexed documents) to classify an input ( can be simple text or a structured document).
org.apache.lucene.classification.document
Uses already seen data (the indexed documents) to classify new documents.
org.apache.lucene.classification.utils
Utilities for evaluation, data preparation, etc.

## Uses of Classifier in org.apache.lucene.classification

Classes in org.apache.lucene.classification that implement Classifier
Modifier and Type
Class
Description
`class`
`BM25NBClassifier`
A classifier approximating naive bayes classifier by using pure queries on BM25.
`class`
`BooleanPerceptronClassifier`
A perceptron (see `http://en.wikipedia.org/wiki/Perceptron`) based `Boolean` `Classifier`.
`class`
`CachingNaiveBayesClassifier`
A simplistic Lucene based NaiveBayes classifier, with caching feature, see `http://en.wikipedia.org/wiki/Naive_Bayes_classifier`
`class`
`KNearestFuzzyClassifier`
A k-Nearest Neighbor classifier based on `NearestFuzzyQuery`.
`class`
`KNearestNeighborClassifier`
A k-Nearest Neighbor classifier (see `http://en.wikipedia.org/wiki/K-nearest_neighbors` ) based on `MoreLikeThis`
`class`
`SimpleNaiveBayesClassifier`
A simplistic Lucene based NaiveBayes classifier, see `http://en.wikipedia.org/wiki/Naive_Bayes_classifier`

## Uses of Classifier in org.apache.lucene.classification.document

Classes in org.apache.lucene.classification.document that implement Classifier
Modifier and Type
Class
Description
`class`
`KNearestNeighborDocumentClassifier`
A k-Nearest Neighbor Document classifier (see `http://en.wikipedia.org/wiki/K-nearest_neighbors`) based on `MoreLikeThis` .
`class`
`SimpleNaiveBayesDocumentClassifier`
A simplistic Lucene based NaiveBayes classifier, see `http://en.wikipedia.org/wiki/Naive_Bayes_classifier`

## Uses of Classifier in org.apache.lucene.classification.utils

Methods in org.apache.lucene.classification.utils with parameters of type Classifier
Modifier and Type
Method
Description
`static <T> ConfusionMatrixGenerator.ConfusionMatrix`
ConfusionMatrixGenerator.`getConfusionMatrix(IndexReader reader, Classifier<T> classifier, String classFieldName, String textFieldName, long timeoutMilliseconds)`
get the `ConfusionMatrixGenerator.ConfusionMatrix` of a given `Classifier`, generated on the given `IndexReader`, class and text fields.