edu.umn.cs.nlp.mt.chiang2007
Class ChartCellEntry

java.lang.Object
  extended by edu.umn.cs.nlp.mt.huangchiang2005.Vertex<RuleApplication,Translation>
      extended by edu.umn.cs.nlp.mt.chiang2007.ChartCellEntry
All Implemented Interfaces:
Scorable

public class ChartCellEntry
extends Vertex<RuleApplication,Translation>
implements Scorable

Represents a symbol that spans a portion of a parse chart.

The k-best extraction technique used in Huang & Chiang (2005) requires that a parse chart be viewed as a hypergraph. In that context, a ChartCellEntry serves as a vertex in a hypergraph.

Version:
$LastChangedDate: 2007-11-09 10:04:34 -0600 (Fri, 09 Nov 2007) $
Author:
Lane Schwartz
See Also:
"Better k-best Parsing" by Liang Huang & David Chiang (IWPT, 2005)

Field Summary
 
Fields inherited from class edu.umn.cs.nlp.mt.huangchiang2005.Vertex
derivations, incomingHyperarcs
 
Constructor Summary
ChartCellEntry(String symbol, int b, double beta)
          Chart cell with pruning parameters
 
Method Summary
 String getElidedTargetLanguagePhrase()
          Gets the possibly elided target language phrase which corresponds to this cell entry.
 LoglinearTranslationFeatures getFeatures()
          Gets the loglinear feature values for this ChartCellEntry.
 double getRawScore()
          Gets the score of this chart cell entry.
 double getScore()
          Gets the score of this chart cell entry for use in pruning.
 String getSymbol()
          Gets the symbol stored in this ChartCellEntry.
 String toString()
          Returns a String object representing this ChartCellEntry.
 
Methods inherited from class edu.umn.cs.nlp.mt.huangchiang2005.Vertex
add, backwardStar, getBestDerivations, getDerivation, getDerivations, inDegree, merge, merge
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

ChartCellEntry

public ChartCellEntry(String symbol,
                      int b,
                      double beta)
Chart cell with pruning parameters

Parameters:
symbol -
b -
beta -
Method Detail

getSymbol

public String getSymbol()
Gets the symbol stored in this ChartCellEntry.

Returns:
the symbol stored in this ChartCellEntry

toString

public String toString()
Returns a String object representing this ChartCellEntry.

Overrides:
toString in class Object
Returns:
a String object representing this ChartCellEntry

getScore

public double getScore()
Gets the score of this chart cell entry for use in pruning. The score returned by this method incorporates Chiang's language model heuristic.

Specified by:
getScore in interface Scorable
Returns:
the score of this chart cell entry for use in pruning

getRawScore

public double getRawScore()
Gets the score of this chart cell entry. The score returned by this method does not incorporate Chiang's language model heuristic.

Returns:
the score of this chart cell entry

getFeatures

public LoglinearTranslationFeatures getFeatures()
Gets the loglinear feature values for this ChartCellEntry.

Returns:
the loglinear feature values for this ChartCellEntry

getElidedTargetLanguagePhrase

public String getElidedTargetLanguagePhrase()
Gets the possibly elided target language phrase which corresponds to this cell entry.

Returns:
the possibly elided target language phrase which corresponds to this cell entry