edu.ucla.sspace.purandare

Class PurandareFirstOrder

java.lang.Object

edu.ucla.sspace.purandare.PurandareFirstOrder

All Implemented Interfaces:

SemanticSpace

public class PurandareFirstOrder
extends Object
implements SemanticSpace

An implementation of the word sense induction algorithm described by Purandare and Pedersen. This implementation is based on the following paper:

• Amruta Purandare and Ted Pedersen. (2004) Word Sense Discrimination by Clustering Contexts in Vector and Similarity Spaces. Proceedings of Conference on Computational Natural Language Learning (CoNLL), pp. 41-48, May 6-7, 2004, Boston, MA.

This class offers one configurable parameter.

Property:
Default: Integer.MAX_VALUE

This property sets the upper-bound on the maximum number of contexts to be clustered for a single word. If there are fewer of contexts than this value, all of the contexts will be used. Users should consider setting this value if a large corpus is to be used, or if the corpus contains many frequently used words after filtering.

Author:

David Jurgens

Field Summary

Fields

Modifier and Type	Field and Description
static String	MAX_CONTEXTS_PER_WORD The property to set the upper-bound on the maximum number of contexts to be clustered for a single word.

Constructor Summary

Constructors

Constructor and Description
PurandareFirstOrder() Creates a new instance of PurandareFirstOrder using the system properties for configuration
PurandareFirstOrder(Properties props) Creates a new instance of PurandareFirstOrder using the provided properties for configuration

Method Summary

Methods

Modifier and Type	Method and Description
String	getSpaceName() Returns a unique string describing the name and configuration of this algorithm.
DoubleVector	getVector(String word) Returns the semantic vector for the provided word.
int	getVectorLength() Returns the length of vectors in this semantic space.
Set<String>	getWords() Returns the set of words that are represented in this semantic space.
void	processDocument(BufferedReader document) Processes the contents of the provided file as a document.
void	processSpace(Properties properties) Once all the documents have been processed, performs any post-processing steps on the data.

Methods inherited from class java.lang.Object

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

Field Detail

MAX_CONTEXTS_PER_WORD

public static final String MAX_CONTEXTS_PER_WORD

The property to set the upper-bound on the maximum number of contexts to be clustered for a single word.

See Also:

Constant Field Values

Constructor Detail

PurandareFirstOrder

public PurandareFirstOrder()

Creates a new instance of PurandareFirstOrder using the system properties for configuration

PurandareFirstOrder

public PurandareFirstOrder(Properties props)

Creates a new instance of PurandareFirstOrder using the provided properties for configuration

Method Detail

processDocument

public void processDocument(BufferedReader document)
                     throws IOException

Processes the contents of the provided file as a document.

Specified by:

processDocument in interface SemanticSpace

Parameters:

document - a reader that allows access to the text of the document

Throws:

IOException - if any error occurs while reading the document

getWords

public Set<String> getWords()

Returns the set of words that are represented in this semantic space.

Specified by:

getWords in interface SemanticSpace

Returns:

the set of words that are represented in this semantic space.

getVector

public DoubleVector getVector(String word)

Returns the semantic vector for the provided word.

Specified by:

getVector in interface SemanticSpace

Parameters:

word - a word that may be in the semantic space

Returns:

The Vector for the provided word or null if the word was not in the space.

processSpace

public void processSpace(Properties properties)

Once all the documents have been processed, performs any post-processing steps on the data. An algorithm should treat this as a no-op if no post-processing is required. Callers may specify the values for any exposed parameters using the properties argument.

By general contract, once this method has been called, processDocument will not be called again.

Specified by:

processSpace in interface SemanticSpace

Parameters:

properties - a set of properties and values that may be used to configure any exposed parameters of the algorithm.

getVectorLength

public int getVectorLength()

Returns the length of vectors in this semantic space. Implementations are left free to define whether the returned value is valid before processSpace is called.

Specified by:

getVectorLength in interface SemanticSpace

getSpaceName

public String getSpaceName()

Returns a unique string describing the name and configuration of this algorithm. Any configurable parameters that would affect the resulting semantic space should be expressed as a part of this name.

Specified by:

getSpaceName in interface SemanticSpace