DependencyVectorSpace (S-Space Package 2.0.1 API)

java.lang.Object
- edu.ucla.sspace.dv.DependencyVectorSpace

All Implemented Interfaces:

DimensionallyInterpretableSemanticSpace<String>, SemanticSpace
```
public class DependencyVectorSpace
extends Object
implements DimensionallyInterpretableSemanticSpace<String>
```
An implementation of the Dependency Vector Space word space model. This model was described in two papers.
- Sebastian Padó and Mirella Lapata. Dependency-based Construction of Semantic Space Models. Computational Linguistics 33(2), 161-199. Available here.
- Sebastian Pado and Mirella Lapata. Constructing Semantic Space Models from Parsed Corpora. Proceedings of ACL-03, Sapporo. Available here.
This algorithm operates on dependency-parsed corpora. Each sentence is represented as a parse tree. When two words are connected by a path in these trees, the path is analyzed to see if it contains semantic information, e.g. the "sbj" path connecting the sentence subject to a verb would be informative. Then the words connected by the path are updated as co-occurring. The algorith has three main points of variation:
- A BasisFunction that maps the the co-occurrence of a word at the end of a path to a specific dimension. For example, a basis function may map each occurrence of a word to a single dimension, or the function might map each occurrence to a different dimension specific to how the work was related.
- A PathWeight for specifying how to value the co-occurrence. For example, each occurrence may have the same value, or the weight could be based on how long is the path that connects them.
- A DependencyPathAcceptor that determines which paths are to be used in counting co-occurrences. Padó and Lapata provide three templates to match against: MinimumTemplateAcceptor, MediumTemplateAcceptor, and MaximumTemplateAcceptor. Each acceptor matches the next smaller's set of paths and additional paths. See Padó and Lapata (2007) for details.
This class offers the following three parameter options for configuration.

Property: "edu.ucla.sspace.dri.DependencyVectorSpace.pathAcceptor"
Default: MinimalTemplateAcceptor
This property sets DependencyPathAcceptor to use for validating dependency paths. If a path is rejected it will not count towards co-occurrences.

Property:
Default: FlatPathWeight
This property sets the method by which co-occurrences are scored. Each valid path is scored by this method. By default all paths are treated the same regardless of length.

Property: "edu.ucla.sspace.dri.DependencyVectorSpace.basisMapping"
Default: WordBasedBasisMapping
This property determine the way in which a path is mapped to a specific dimension in the vector space. By default, only words are used as dimensions; the occurrence of a word at the end of a path is treated the same regardless of the relation connect it or length of the path.

This class is thread-safe for concurrent calls of processDocument. At any given point in processing, the getVector method may be used to access the current semantics of a word. This allows callers to track incremental changes to the semantics as the corpus is processed.
The processSpace method for this class does nothing.
Author:

David Jurgens

See Also:
StructuredVectorSpace, BasisFunction, PathWeight, DependencyPathAcceptor

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`BASIS_MAPPING_PROPERTY` The property for setting the maximal length of any `DependencyPath`.
`static String`	`PATH_ACCEPTOR_PROPERTY` The property for setting the `DependencyPathAcceptor`.
`static String`	`PATH_WEIGHTING_PROPERTY` The property for setting the `DependencyPathWeight`.
`static String`	`PROPERTY_PREFIX` The base prefix for all `DependencyVectorSpace` properties.

Constructor Summary

Constructors
Constructor and Description
`DependencyVectorSpace()` Creates and configures this `DependencyVectorSpace` with the default set of parameters.
`DependencyVectorSpace(Properties properties)` Creates and configures this `DependencyVectorSpace` with the default set of parameters.
`DependencyVectorSpace(Properties properties, int pathLength)` /** Creates and configures this `DependencyVectorSpace` with the default set of parameters.

Method Summary

Methods
Modifier and Type	Method and Description
`String`	`getDimensionDescription(int dimension)` Returns a description of the dependency path feature to which the provided dimension is mapped.
`String`	`getSpaceName()` Returns "`DependencyVectorSpace`" plus this instance's configuration of a basis mapping, path weighting and path acceptor.
`Vector`	`getVector(String term)` 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)` Extracts all the parsed sentences in the document and then updates the co-occurrence values for those paths matching the loaded set of templates, according to this instance's `BasisFunction`.
`void`	`processSpace(Properties properties)` Does nothing.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - PROPERTY_PREFIX
```
public static final String PROPERTY_PREFIX
```
    The base prefix for all DependencyVectorSpace properties.
    
    See Also:
    Constant Field Values
  - PATH_ACCEPTOR_PROPERTY
```
public static final String PATH_ACCEPTOR_PROPERTY
```
    The property for setting the DependencyPathAcceptor.
    
    See Also:
    Constant Field Values
  - PATH_WEIGHTING_PROPERTY
```
public static final String PATH_WEIGHTING_PROPERTY
```
    The property for setting the DependencyPathWeight.
    
    See Also:
    Constant Field Values
  - BASIS_MAPPING_PROPERTY
```
public static final String BASIS_MAPPING_PROPERTY
```
    The property for setting the maximal length of any DependencyPath.
    
    See Also:
    Constant Field Values
- Constructor Detail
  - DependencyVectorSpace
```
public DependencyVectorSpace()
```
    Creates and configures this DependencyVectorSpace with the default set of parameters. The default values are:
    - a WordBasedBasisMapping is used for dimensions;
    - a FlatPathWeight is used to weight accepted paths;
    - and a MinimumTemplateAcceptor is used to filter the paths in a sentence.
  - DependencyVectorSpace
```
public DependencyVectorSpace(Properties properties)
```
    Creates and configures this DependencyVectorSpace with the default set of parameters. The default values are:
    - a WordBasedBasisMapping is used for dimensions;
    - a FlatPathWeight is used to weight accepted paths;
    - and a MinimumTemplateAcceptor is used to filter the paths in a sentence.
  - DependencyVectorSpace
```
public DependencyVectorSpace(Properties properties,
                     int pathLength)
```
    /** Creates and configures this DependencyVectorSpace with the default set of parameters. The default values are:
    - a WordBasedBasisMapping is used for dimensions;
    - a FlatPathWeight is used to weight accepted paths;
    - and a MinimumTemplateAcceptor is used to filter the paths in a sentence.
    Parameters:
    properties - The Properties setting the above options
    pathLength - The maximum valid path length. Must be non-negative. If zero, an the maximum path length used by the DependencyPathAcceptor will be used.
- Method Detail
  - getDimensionDescription
```
public String getDimensionDescription(int dimension)
```
    Returns a description of the dependency path feature to which the provided dimension is mapped.
    
    Specified by:
    
    getDimensionDescription in interface DimensionallyInterpretableSemanticSpace<String>
    
    Parameters:
    dimension - a dimension number
    
    Returns:
    a description of the features for the dimension
  - 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 Vector getVector(String term)
```
    Returns the semantic vector for the provided word.
    
    Specified by:
    
    getVector in interface SemanticSpace
    
    Parameters:
    term - 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.
  - getSpaceName
```
public String getSpaceName()
```
    Returns "DependencyVectorSpace" plus this instance's configuration of a basis mapping, path weighting and path acceptor.
    
    Specified by:
    
    getSpaceName in interface SemanticSpace
  - 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
  - processDocument
```
public void processDocument(BufferedReader document)
                     throws IOException
```
    Extracts all the parsed sentences in the document and then updates the co-occurrence values for those paths matching the loaded set of templates, according to this instance's BasisFunction. Path occurrences are weighted using this instance's PathWeight.
    
    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
  - processSpace
```
public void processSpace(Properties properties)
```
    Does nothing.
    
    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.

Class DependencyVectorSpace

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

PROPERTY_PREFIX

PATH_ACCEPTOR_PROPERTY

PATH_WEIGHTING_PROPERTY

BASIS_MAPPING_PROPERTY

Constructor Detail

DependencyVectorSpace

DependencyVectorSpace

DependencyVectorSpace

Method Detail

getDimensionDescription

getWords

getVector

getSpaceName

getVectorLength

processDocument

processSpace