com.aliasi.spell.FixedWeightEditDistance Maven / Gradle / Ivy
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/*
* LingPipe v. 4.1.0
* Copyright (C) 2003-2011 Alias-i
*
* This program is licensed under the Alias-i Royalty Free License
* Version 1 WITHOUT ANY WARRANTY, without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the Alias-i
* Royalty Free License Version 1 for more details.
*
* You should have received a copy of the Alias-i Royalty Free License
* Version 1 along with this program; if not, visit
* http://alias-i.com/lingpipe/licenses/lingpipe-license-1.txt or contact
* Alias-i, Inc. at 181 North 11th Street, Suite 401, Brooklyn, NY 11211,
* +1 (718) 290-9170.
*/
package com.aliasi.spell;
import com.aliasi.util.AbstractExternalizable;
import com.aliasi.util.Compilable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.Serializable;
/**
* A FixedWeightEditDistance sets constant weights for
* the edit operations for weighted edit distance.
*
* Subclasses of this class may override any of the weight
* implementations.
*
*
Serialization and Compilation
*
* Serialization and compilation both do the same thing, namely
* store the fixed weight edit distance for reading in later.
*
* @author Bob Carpenter
* @version 3.8
* @since LingPipe2.0
*/
public class FixedWeightEditDistance
extends WeightedEditDistance
implements Compilable, Serializable {
static final long serialVersionUID = 6520949001598595981L;
private final double mMatchWeight;
private final double mDeleteWeight;
private final double mInsertWeight;
private final double mSubstituteWeight;
private final double mTransposeWeight;
/**
* Construct a weighted edit distance with the specified constant
* weights for edits.
*
*
See the {@link WeightedEditDistance} class documewntation
* for more information on similarity versus dissimialrity
* measures.
*
* @param matchWeight Weight for matching.
* @param deleteWeight Weight for deleting.
* @param insertWeight Weight for inserting.
* @param substituteWeight Weight for substituting.
* @param transposeWeight Weight for transposing.
*/
public FixedWeightEditDistance(double matchWeight,
double deleteWeight,
double insertWeight,
double substituteWeight,
double transposeWeight) {
mMatchWeight = matchWeight;
mDeleteWeight = deleteWeight;
mInsertWeight = insertWeight;
mSubstituteWeight = substituteWeight;
mTransposeWeight = transposeWeight;
}
/**
* Constructs an edit distance where the match weight is zero and
* all other weights are positive infinity. If none of the weight
* methods are overridden in a sublcass, the result is a string
* distance that is zero between identical strings and negative
* infinity otherwise.
*/
public FixedWeightEditDistance() {
this(0.0,
Double.NEGATIVE_INFINITY, Double.NEGATIVE_INFINITY,
Double.NEGATIVE_INFINITY, Double.NEGATIVE_INFINITY);
}
/**
* Returns a string-based representation of this fixed-weight
* edit distance's parameters.
*
* @return String-based representation of this distance.
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("Edit Distance Class=" + getClass());
sb.append("FixedWeightEditDistance costs:");
sb.append(" match weight=" + mMatchWeight);
sb.append(" insert weight=" + mInsertWeight);
sb.append(" delete weight=" + mDeleteWeight);
sb.append(" substitute weight=" + mSubstituteWeight);
sb.append(" transpose weight=" + mTransposeWeight);
return sb.toString();
}
private Object writeReplace() {
return new Externalizer(this);
}
private static class Externalizer extends AbstractExternalizable {
private static final long serialVersionUID = 636473803792927790L;
private final FixedWeightEditDistance mFWED;
public Externalizer() {
mFWED = null;
}
public Externalizer(FixedWeightEditDistance fwed) {
mFWED = fwed;
}
@Override
public void writeExternal(ObjectOutput objOut) throws IOException {
objOut.writeDouble(mFWED.mMatchWeight);
objOut.writeDouble(mFWED.mDeleteWeight);
objOut.writeDouble(mFWED.mInsertWeight);
objOut.writeDouble(mFWED.mSubstituteWeight);
objOut.writeDouble(mFWED.mTransposeWeight);
}
@Override
public Object read(ObjectInput objIn) throws IOException {
return new FixedWeightEditDistance(objIn.readDouble(),
objIn.readDouble(),
objIn.readDouble(),
objIn.readDouble(),
objIn.readDouble());
}
}
/**
* Writes a compiled version of this edit distance to the
* specified object output. If this method is called on an
* instance of a subclass, only the fixed weight component is
* compiled. Thus subclasses should either override this method
* or throw an {@link UnsupportedOperationException}.
*
* @param objOut The object output to which this fixed weight
* edit distance is written.
* @throws IOException If there is an I/O error while writing.
*/
public void compileTo(ObjectOutput objOut) throws IOException {
objOut.writeObject(new Externalizer(this));
}
/**
* Returns the constant weight of matching the specified character.
*
* @param cMatched Character matched.
* @return Weight of matching character.
*/
@Override
public double matchWeight(char cMatched) {
return mMatchWeight;
}
/**
* Returns the constant weight of deleting the specified character.
*
* @param cDeleted Character deleted.
* @return Weight of deleting character.
*/
@Override
public double deleteWeight(char cDeleted) {
return mDeleteWeight;
}
/**
* Returns the constant weight of inserting the specified character.
*
* @param cInserted Character inserted.
* @return Weight of inserting character.
*/
@Override
public double insertWeight(char cInserted) {
return mInsertWeight;
}
/**
* Returns the constant weight of substituting the inserted character for
* the deleted character.
*
* @param cDeleted Deleted character.
* @param cInserted Inserted character.
* @return The weight of substituting the inserted character for
* the deleted character.
*/
@Override
public double substituteWeight(char cDeleted, char cInserted) {
return mSubstituteWeight;
}
/**
* Returns the constant weight of transposing the specified characters. Note
* that the order of arguments follows that of the input.
*
* @param cFirst First character in input.
* @param cSecond Second character in input.
* @return The weight of transposing the specified characters.
*/
@Override
public double transposeWeight(char cFirst, char cSecond) {
return mTransposeWeight;
}
}