/*
* Copyright 1998-2014 University Corporation for Atmospheric Research/Unidata
*
* Portions of this software were developed by the Unidata Program at the
* University Corporation for Atmospheric Research.
*
* Access and use of this software shall impose the following obligations
* and understandings on the user. The user is granted the right, without
* any fee or cost, to use, copy, modify, alter, enhance and distribute
* this software, and any derivative works thereof, and its supporting
* documentation for any purpose whatsoever, provided that this entire
* notice appears in all copies of the software, derivative works and
* supporting documentation. Further, UCAR requests that the user credit
* UCAR/Unidata in any publications that result from the use of this
* software or in any product that includes this software. The names UCAR
* and/or Unidata, however, may not be used in any advertising or publicity
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*
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA BE LIABLE FOR ANY SPECIAL,
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* WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package ucar.units;
import net.jcip.annotations.Immutable;
import java.io.Serializable;
/**
* Provides support for a Base/exponent pair. Instances of this class are
* immutable.
*
* @author Steven R. Emmerson
*/
@Immutable
public final class Factor implements Serializable {
private static final long serialVersionUID = 1L;
/**
* The Base entity.
*
* @serial
*/
private final Base _base;
/**
* The exponent.
*
* @serial
*/
private final int _exponent;
/**
* Constructs from a Base. The exponent is set to unity.
*
* @param base
* The base entity.
*/
public Factor(final Base base) {
this(base, 1);
}
/**
* Constructs from a Factor and an exponent.
*
* @param factor
* The factor.
* @param exponent
* The exponent.
*/
public Factor(final Factor factor, final int exponent) {
this(factor.getBase(), exponent);
}
/**
* Constructs from a Base and an exponent.
*
* @param base
* The base entity.
* @param exponent
* The exponent.
*/
public Factor(final Base base, final int exponent) {
_base = base;
_exponent = exponent;
}
/**
* Returns the Base entity.
*
* @return The Base entity.
*/
public Base getBase() {
return _base;
}
/**
* Returns the identifier of the Base entity.
*
* @return The identifier of the Base entity (symbol or name).
*/
public String getID() {
return getBase().getID();
}
/**
* Returns the exponent of the Base entity.
*
* @return The exponent of the Base entity.
*/
public int getExponent() {
return _exponent;
}
/**
* Raises this Factor to a power.
*
* @param power
* The power by which to raise this Factor.
* @return The Factor resulting from raising this Factor to the given power.
*/
public Factor pow(final int power) {
return new Factor(getBase(), getExponent() * power);
}
/**
* Returns the string representation of this Factor.
*
* @return The string representation of this Factor.
*/
@Override
public final String toString() {
return getExponent() == 0
? ""
: getExponent() == 1
? getBase().toString()
: getBase().toString() + getExponent();
}
/**
* Indicates if this Factor is semantically identical to another object.
*
* @param object
* The object.
* @return <code>true</code> if and only if this Factor is semantically
* identical to <code>object<
* /code>.
*/
@Override
public boolean equals(final Object object) {
boolean equals;
if (this == object) {
equals = true;
}
else if (!(object instanceof Factor)) {
equals = false;
}
else {
final Factor that = (Factor) object;
equals = getExponent() != that.getExponent()
? false
: getExponent() == 0 || getBase().equals(that.getBase());
}
return equals;
}
/**
* Returns the hash code of this instance.
*
* @return The hash code of this instance.
*/
@Override
public int hashCode() {
return getExponent() == 0
? getClass().hashCode()
: getExponent() ^ getBase().hashCode();
}
/**
* Indicates if this Factor is the reciprocal of another Factor.
*
* @param that
* The other factor.
* @return <code>true</code> if and only if this Factor is the reciprocal of
* <code>that</code>.
*/
public boolean isReciprocalOf(final Factor that) {
return getBase().equals(that.getBase())
&& getExponent() == -that.getExponent();
}
/**
* Indicates if this factor is dimensionless. A Factor is dimensionless if
* and only if the exponent is zero or the Base entity is dimensionless.
*
* @return <code>true</code> if and only if this Factor is dimensionless.
*/
public boolean isDimensionless() {
return getExponent() == 0 || getBase().isDimensionless();
}
}