org.carrot2.text.preprocessing

Class DocumentAssigner

java.lang.Object

org.carrot2.text.preprocessing.DocumentAssigner

@Bindable(prefix="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

Fields

Modifier and Type	Field and Description
boolean	exactPhraseAssignment Only exact phrase assignments.
int	minClusterSize Determines the minimum number of documents in each cluster.

Constructor Summary

Constructors

Constructor and Description
DocumentAssigner()

Method Summary

Methods

Modifier and Type	Method and Description
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

@Input
@Processing
@Attribute
@Label(value="Exact phrase assignment")
@Level(value=MEDIUM)
@Group(value="Preprocessing")
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.

minClusterSize

@Input
@Processing
@Attribute
@IntRange(min=1,
          max=100)
@Label(value="Minimum cluster size")
@Level(value=MEDIUM)
@Group(value="Preprocessing")
public int minClusterSize

Determines the minimum number of documents in each cluster.

Constructor Detail

DocumentAssigner

public DocumentAssigner()

Method Detail

assign

public void assign(PreprocessingContext context)

Assigns document to label candidates.