# 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.