org.carrot2.text.preprocessing
Class DocumentAssigner

java.lang.Object
  org.carrot2.text.preprocessing.DocumentAssigner

public class DocumentAssigner
extends Object

Assigns document to label candidates. For each label candidate from PreprocessingContext.AllLabels.featureIndex an BitSet with the assigned documents is constructed. The assignment algorithm is rather simple: in order to be assigned to a label, a document must contain at least one occurrence of each non-stop word from the label.

This class saves the following results to the PreprocessingContext :

• PreprocessingContext.AllLabels.documentIndices

This class requires that Tokenizer, CaseNormalizer, StopListMarker, PhraseExtractor and LabelFilterProcessor be invoked first.

Field Summary

boolean	exactPhraseAssignment Only exact phrase assignments.
int	minClusterSize Determines the minimum number of documents in each cluster.

Constructor Summary

DocumentAssigner()

Method Summary

void	assign(PreprocessingContext context) Assigns document to label candidates.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

exactPhraseAssignment

public boolean exactPhraseAssignment

Only exact phrase assignments. Assign only documents that contain the label in its original form, including the order of words. Enabling this option will cause less documents to be put in clusters, which result in higher precision of assignment, but also a larger "Other Topics" group. Disabling this option will cause more documents to be put in clusters, which will make the "Other Topics" cluster smaller, but also lower the precision of cluster-document assignments.

Attribute label:

Exact phrase assignment

Attribute level:

Medium

Attribute group:

Preprocessing

minClusterSize

public int minClusterSize

Determines the minimum number of documents in each cluster.

Attribute label:

Minimum cluster size

Attribute level:

Medium

Attribute group:

Preprocessing

Constructor Detail

DocumentAssigner

public DocumentAssigner()

Method Detail

assign

public void assign(PreprocessingContext context)

Assigns document to label candidates.