package de.lmu.ifi.dbs.elki.distance.distancevalue;
/*
This file is part of ELKI:
Environment for Developing KDD-Applications Supported by Index-Structures
Copyright (C) 2012
Ludwig-Maximilians-Universität München
Lehr- und Forschungseinheit für Datenbanksysteme
ELKI Development Team
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
import de.lmu.ifi.dbs.elki.data.Bit;
import de.lmu.ifi.dbs.elki.utilities.exceptions.ExceptionMessages;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.regex.Pattern;
/**
* Provides a Distance for a bit-valued distance.
*
* @author Arthur Zimek
*/
public class BitDistance extends NumberDistance<BitDistance, Bit> {
/**
* The static factory instance
*/
public final static BitDistance FACTORY = new BitDistance();
/**
* The distance value
*/
private boolean value;
/**
* Generated serial version UID
*/
private static final long serialVersionUID = 6514853467081717551L;
/**
* Empty constructor for serialization purposes.
*/
public BitDistance() {
super();
}
/**
* Constructs a new BitDistance object that represents the bit argument.
*
* @param bit the value to be represented by the BitDistance.
*/
public BitDistance(boolean bit) {
super();
this.value = bit;
}
/**
* Constructs a new BitDistance object that represents the bit argument.
*
* @param bit the value to be represented by the BitDistance.
*/
public BitDistance(Bit bit) {
super();
this.value = bit.bitValue();
}
@Override
public BitDistance fromDouble(double val) {
return new BitDistance(val > 0);
}
@Override
public BitDistance plus(BitDistance distance) {
return new BitDistance(this.bitValue() || distance.bitValue());
}
@Override
public BitDistance minus(BitDistance distance) {
return new BitDistance(this.bitValue() ^ distance.bitValue());
}
/**
* Returns the value of this BitDistance as a boolean.
*
* @return the value as a boolean
*/
public boolean bitValue() {
return this.value;
}
/**
* Writes the bit value of this BitDistance to the specified stream.
*/
@Override
public void writeExternal(ObjectOutput out) throws IOException {
out.writeBoolean(this.bitValue());
}
/**
* Reads the bit value of this BitDistance from the specified stream.
*/
@Override
public void readExternal(ObjectInput in) throws IOException {
setValue(new Bit(in.readBoolean()));
}
/**
* Returns the number of Bytes this distance uses if it is written to an
* external file.
*
* @return 1 (1 Byte for a boolean value)
*/
@Override
public int externalizableSize() {
return 1;
}
@Override
public Bit getValue() {
return new Bit(this.value);
}
@Override
void setValue(Bit value) {
this.value = value.bitValue();
}
@Override
public double doubleValue() {
return value ? 1.0 : 0.0;
}
@Override
public long longValue() {
return value ? 1 : 0;
}
@Override
public int intValue() {
return value ? 1 : 0;
}
@Override
public int compareTo(BitDistance other) {
return this.intValue() - other.intValue();
}
@Override
public BitDistance parseString(String val) throws IllegalArgumentException {
if(testInputPattern(val)) {
return new BitDistance(Bit.valueOf(val).bitValue());
}
else {
throw new IllegalArgumentException("Given pattern \"" + val + "\" does not match required pattern \"" + requiredInputPattern() + "\"");
}
}
@Override
public BitDistance infiniteDistance() {
return new BitDistance(true);
}
@Override
public BitDistance nullDistance() {
return new BitDistance(false);
}
@Override
public BitDistance undefinedDistance() {
throw new UnsupportedOperationException(ExceptionMessages.UNSUPPORTED_UNDEFINED_DISTANCE);
}
@Override
public Pattern getPattern() {
return Bit.BIT_PATTERN;
}
@Override
public boolean isInfiniteDistance() {
return false;
}
@Override
public boolean isNullDistance() {
return (value == false);
}
@Override
public boolean isUndefinedDistance() {
return false;
}
}