/*
* Redberry: symbolic tensor computations.
*
* Copyright (c) 2010-2013:
* Stanislav Poslavsky <stvlpos@mail.ru>
* Bolotin Dmitriy <bolotin.dmitriy@gmail.com>
*
* This file is part of Redberry.
*
* Redberry is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Redberry 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Redberry. If not, see <http://www.gnu.org/licenses/>.
*/
package cc.redberry.core.number;
import org.apache.commons.math3.exception.MathIllegalArgumentException;
import org.apache.commons.math3.fraction.BigFraction;
import org.apache.commons.math3.fraction.FractionConversionException;
import java.io.Serializable;
import java.math.BigInteger;
import static cc.redberry.core.number.NumberUtils.*;
/**
* Representation of a rational number without any overflow. This class is a
* wrapper of {@link BigInteger}.
* <p/>
* <p>This class implements mathematical operations declared in
* {@link cc.redberry.core.number.Number} as operations with in the following
* way. If argument is {@link Numeric}, the result will be {@code Numeric} too.
* For example, 2 / 3 +1.0 will give 1.666666 and so on. If argument is {@code Rational}
* number, the result will be {@code Rational} too.
*
* @author Stanislav Poslavsky
* @see Number
* @see Numeric
* @see BigFraction
*/
public final class Rational extends Real implements Serializable {
/**
* A fraction representing "2 / 1".
*/
public static final Rational TWO = new Rational(2);
/**
* A fraction representing "4 / 1".
*/
public static final Rational FOUR = new Rational(4);
/**
* A fraction representing "-2 / 1".
*/
public static final Rational MINUS_TWO = new Rational(-2);
/**
* A fraction representing "1".
*/
public static final Rational ONE = new Rational(1);
/**
* A fraction representing "0".
*/
public static final Rational ZERO = new Rational(0);
/**
* A fraction representing "-1 / 1".
*/
public static final Rational MINUS_ONE = new Rational(-1);
/**
* A fraction representing "4/5".
*/
public static final Rational FOUR_FIFTHS = new Rational(4, 5);
/**
* A fraction representing "1/5".
*/
public static final Rational ONE_FIFTH = new Rational(1, 5);
/**
* A fraction representing "1/2".
*/
public static final Rational ONE_HALF = new Rational(1, 2);
/**
* A fraction representing "1/2".
*/
public static final Rational MINUSE_ONE_HALF = new Rational(-1, 2);
/**
* A fraction representing "1/4".
*/
public static final Rational ONE_QUARTER = new Rational(1, 4);
/**
* A fraction representing "1/3".
*/
public static final Rational ONE_THIRD = new Rational(1, 3);
/**
* A fraction representing "3/5".
*/
public static final Rational THREE_FIFTHS = new Rational(3, 5);
/**
* A fraction representing "3/4".
*/
public static final Rational THREE_QUARTERS = new Rational(3, 4);
/**
* A fraction representing "2/5".
*/
public static final Rational TWO_FIFTHS = new Rational(2, 5);
/**
* A fraction representing "2/3".
*/
public static final Rational TWO_THIRDS = new Rational(2, 3);
/**
* Serializable version identifier.
*/
private static final long serialVersionUID = -5630213147331578515L;
/*
* rational value
*/
private final BigFraction fraction;
public Rational(BigFraction fraction) {
checkNotNull(fraction);
this.fraction = fraction;
}
/**
* @see BigFraction#BigFraction(java.math.BigInteger)
*/
public Rational(BigInteger num) {
checkNotNull(num);
fraction = new BigFraction(num);
}
/**
* @see BigFraction#BigFraction(java.math.BigInteger, java.math.BigInteger)
*/
public Rational(BigInteger num, BigInteger den) {
checkNotNull(num);
checkNotNull(den);
fraction = new BigFraction(num, den);
}
/**
* @see BigFraction#BigFraction(double)
*/
public Rational(double value) throws MathIllegalArgumentException {
fraction = new BigFraction(value);
}
/**
* @see BigFraction#BigFraction(double, double, int)
*/
public Rational(double value, double epsilon, int maxIterations) throws FractionConversionException {
fraction = new BigFraction(value, epsilon, maxIterations);
}
/**
* @see BigFraction#BigFraction(double, int)
*/
public Rational(double value, int maxDenominator) throws FractionConversionException {
fraction = new BigFraction(value, maxDenominator);
}
/**
* @see BigFraction#BigFraction(int)
*/
public Rational(int num) {
fraction = new BigFraction(num);
}
/**
* @see BigFraction#BigFraction(int, int)
*/
public Rational(int num, int den) {
fraction = new BigFraction(num, den);
}
/**
* @see BigFraction#BigFraction(long)
*/
public Rational(long num) {
fraction = new BigFraction(num);
}
/**
* @see BigFraction#BigFraction(long, long)
*/
public Rational(long num, long den) {
fraction = new BigFraction(num, den);
}
public BigFraction getBigFraction() {
return fraction;
}
@Override
public long longValue() {
return fraction.longValue();
}
@Override
public int intValue() {
return fraction.intValue();
}
@Override
public float floatValue() {
return fraction.floatValue();
}
@Override
public double doubleValue() {
return fraction.doubleValue();
}
@Override
public int hashCode() {
return fraction.abs().hashCode();
}
@Override
public boolean equals(Object obj) {
if (obj == null)
return false;
if (!(obj instanceof Number))
return false;
if (obj instanceof Rational)
return fraction.equals(((Rational) obj).fraction);
else
return ((Numeric) obj).doubleValue() == doubleValue();
}
@Override
public String toString() {
return fraction.getNumerator().toString() + (fraction.getDenominator().equals(BigInteger.ONE) ? "" : ("/" + fraction.getDenominator().toString()));
}
@Override
public boolean isInfinite() {
return false;
}
@Override
public boolean isNaN() {
return false;
}
@Override
public Real add(Real arg0) {
checkNotNull(arg0);
if (arg0 instanceof Numeric)
return arg0.add(this);
return createRational(fraction.add(((Rational) arg0).fraction));
}
@Override
public Real divide(Real arg0) {
checkNotNull(arg0);
if (arg0 instanceof Numeric || arg0.isZero())
return createNumeric(fraction.doubleValue() / arg0.doubleValue());
return createRational(fraction.divide(((Rational) arg0).fraction));
}
@Override
public Real multiply(double d) {
return createNumeric(d * fraction.doubleValue());
}
@Override
public Rational multiply(int arg0) {
return arg0 == 1 ? this : arg0 == 0 ? ZERO : new Rational(fraction.multiply(arg0));
}
@Override
public Real multiply(Real arg0) {
checkNotNull(arg0);
if (arg0 instanceof Numeric)
return arg0.multiply(this);
return arg0.isOne() ? this : arg0.isZero() ? ZERO : createRational(fraction.multiply(((Rational) arg0).fraction));
}
public Rational multiply(Rational arg0) {
checkNotNull(arg0);
return arg0.isOne() ? this : arg0.isZero() ? ZERO : createRational(fraction.multiply((arg0).fraction));
}
@Override
public Rational negate() {
return createRational(fraction.negate());
}
@Override
public Rational reciprocal() {
return createRational(fraction.reciprocal());
}
@Override
public Real subtract(Real arg0) {
checkNotNull(arg0);
if (arg0 instanceof Numeric)
return new Numeric(fraction.doubleValue() - arg0.doubleValue());
return createRational(fraction.subtract(((Rational) arg0).fraction));
}
@Override
public Rational subtract(BigFraction fraction) {
checkNotNull(fraction);
return createRational(this.fraction.subtract(fraction));
}
@Override
public Rational subtract(long l) {
return l == 0 ? this : createRational(fraction.subtract(l));
}
@Override
public Rational subtract(int i) {
return new Rational(fraction.subtract(i));
}
@Override
public Rational subtract(BigInteger bg) {
NumberUtils.checkNotNull(bg);
return new Rational(fraction.subtract(bg));
}
public Rational reduce() {
return new Rational(fraction.reduce());
}
@Override
public Numeric pow(double exponent) {
return new Numeric(fraction.pow(exponent));
}
@Override
public Rational pow(BigInteger exponent) {
NumberUtils.checkNotNull(exponent);
return new Rational(fraction.pow(exponent));
}
@Override
public Rational pow(long exponent) {
return new Rational(fraction.pow(exponent));
}
@Override
public Rational pow(int exponent) {
return new Rational(fraction.pow(exponent));
}
public double percentageValue() {
return fraction.percentageValue();
}
@Override
public Rational multiply(BigFraction fraction) {
NumberUtils.checkNotNull(fraction);
return new Rational(fraction.multiply(fraction));
}
@Override
public Rational multiply(long l) {
return new Rational(fraction.multiply(l));
}
@Override
public Rational multiply(BigInteger bg) {
NumberUtils.checkNotNull(bg);
return new Rational(fraction.multiply(bg));
}
public long getNumeratorAsLong() {
return fraction.getNumeratorAsLong();
}
public int getNumeratorAsInt() {
return fraction.getNumeratorAsInt();
}
public BigInteger getNumerator() {
return fraction.getNumerator();
}
public long getDenominatorAsLong() {
return fraction.getDenominatorAsLong();
}
public int getDenominatorAsInt() {
return fraction.getDenominatorAsInt();
}
public BigInteger getDenominator() {
return fraction.getDenominator();
}
@Override
public Rational divide(BigFraction fraction) {
NumberUtils.checkNotNull(fraction);
return new Rational(fraction.divide(fraction));
}
@Override
public Rational divide(long l) {
return new Rational(fraction.divide(l));
}
@Override
public Rational divide(int i) {
return new Rational(fraction.divide(i));
}
@Override
public Rational divide(BigInteger bg) {
NumberUtils.checkNotNull(bg);
return new Rational(fraction.divide(bg));
}
@Override
public Real divide(double d) {
return new Numeric(fraction.doubleValue() / d);
}
@Override
public Rational add(BigFraction fraction) {
NumberUtils.checkNotNull(fraction);
return new Rational(fraction.add(fraction));
}
@Override
public Rational add(long l) {
return new Rational(fraction.add(l));
}
@Override
public Rational add(BigInteger bg) {
NumberUtils.checkNotNull(bg);
return new Rational(fraction.add(bg));
}
@Override
public Real add(double d) {
return new Numeric(d + doubleValue());
}
@Override
public Rational add(int i) {
return new Rational(fraction.add(i));
}
@Override
public Real subtract(double d) {
return new Numeric(this.doubleValue() - d);
}
@Override
public Rational abs() {
return new Rational(fraction.abs());
}
@Override
public Numeric getNumericValue() {
return new Numeric(doubleValue());
}
@Override
public int compareTo(Real o) {
NumberUtils.checkNotNull(o);
if (o instanceof Numeric)
return Double.compare(doubleValue(), o.doubleValue());
return fraction.compareTo(((Rational) o).fraction);
}
@Override
public boolean isNumeric() {
return false;
}
@Override
public boolean isZero() {
//Here we do not use fraction.equals() because it has low performence
return fraction.getNumerator().equals(BigInteger.ZERO);//.equals(BigFraction.ZERO);
}
@Override
public boolean isOne() {
//Here we do not use fraction.equals() because it has low performence
return fraction.getNumerator().equals(BigInteger.ONE) && fraction.getDenominator().equals(BigInteger.ONE);//equals(BigFraction.ONE);
}
/*
* Chached instenance for comparing with it (for performance)
*/
private static final BigInteger BI_MINUS_ONE = new BigInteger("-1");
@Override
public boolean isMinusOne() {
//Here we do not use fraction.equals() because it has low performence
return fraction.getNumerator().equals(BI_MINUS_ONE) && fraction.getDenominator().equals(BigInteger.ONE);//equals(BigFraction.ONE);
}
@Override
public int signum() {
return fraction.getNumerator().signum();
}
@Override
public boolean isInteger() {
return fraction.getDenominator().compareTo(BigInteger.ONE) == 0;
}
@Override
public boolean isNatural() {
return fraction.getNumerator().signum() >= 0 && isInteger();
}
}