Class Fraction
- java.lang.Object
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- java.lang.Number
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- org.apache.commons.numbers.fraction.Fraction
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- All Implemented Interfaces:
Serializable,Comparable<Fraction>,Addition<Fraction>,Multiplication<Fraction>,NativeOperators<Fraction>
public final class Fraction extends Number implements Comparable<Fraction>, NativeOperators<Fraction>, Serializable
Representation of a rational number.The number is expressed as the quotient
p/qof two 32-bit integers, a numeratorpand a non-zero denominatorq.This class is immutable. Rational number
- See Also:
- Serialized Form
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description Fractionabs()Returns the absolute value of this fraction.Fractionadd(int value)Adds the specifiedvalueto this fraction, returning the result in reduced form.Fractionadd(Fraction value)Adds the specifiedvalueto this fraction, returning the result in reduced form.intcompareTo(Fraction other)Compares this object with the specified object for order using the signed magnitude.Fractiondivide(int value)Divide this fraction by the passedvalue, returning the result in reduced form.Fractiondivide(Fraction value)Divide this fraction by the passedvalue, returning the result in reduced form.doubledoubleValue()Returns thedoublevalue closest to this fraction.booleanequals(Object other)Test for equality with another object.floatfloatValue()Returns thefloatvalue closest to this fraction.static Fractionfrom(double value)Create a fraction given the double value.static Fractionfrom(double value, double epsilon, int maxIterations)Create a fraction given the double value and maximum error allowed.static Fractionfrom(double value, int maxDenominator)Create a fraction given the double value and maximum denominator.intgetDenominator()Access the denominator as anint.intgetNumerator()Access the numerator as anint.inthashCode()intintValue()Returns the whole number part of the fraction.booleanisOne()booleanisZero()longlongValue()Returns the whole number part of the fraction.Fractionmultiply(int value)Multiply this fraction by the passedvalue, returning the result in reduced form.Fractionmultiply(Fraction value)Multiply this fraction by the passedvalue, returning the result in reduced form.Fractionnegate()static Fractionof(int num)Create a fraction given the numerator.static Fractionof(int num, int den)Create a fraction given the numerator and denominator.Fractionone()static Fractionparse(String s)Returns aFractioninstance representing the specified strings.Fractionpow(int exponent)Returns aFractionwhose value isthisexponent, returning the result in reduced form.Fractionreciprocal()intsignum()Retrieves the sign of this fraction.Fractionsubtract(int value)Subtracts the specifiedvaluefrom this fraction, returning the result in reduced form.Fractionsubtract(Fraction value)Subtracts the specifiedvaluefrom this fraction, returning the result in reduced form.StringtoString()Returns theStringrepresenting this fraction.Fractionzero()-
Methods inherited from class java.lang.Number
byteValue, shortValue
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Method Detail
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from
public static Fraction from(double value)
Create a fraction given the double value.- Parameters:
value- Value to convert to a fraction.- Returns:
- a new instance.
- Throws:
IllegalArgumentException- if the givenvalueis NaN or infinite.ArithmeticException- if the continued fraction failed to converge.
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from
public static Fraction from(double value, double epsilon, int maxIterations)
Create a fraction given the double value and maximum error allowed.References:
- Continued Fraction equations (11) and (22)-(26)
- Parameters:
value- Value to convert to a fraction.epsilon- Maximum error allowed. The resulting fraction is withinepsilonofvalue, in absolute terms.maxIterations- Maximum number of convergents.- Returns:
- a new instance.
- Throws:
IllegalArgumentException- if the givenvalueis NaN or infinite;epsilonis not positive; ormaxIterations < 1.ArithmeticException- if the continued fraction failed to converge.
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from
public static Fraction from(double value, int maxDenominator)
Create a fraction given the double value and maximum denominator.References:
- Continued Fraction equations (11) and (22)-(26)
Note: The magnitude of the
maxDenominatoris used allowing use ofInteger.MIN_VALUEfor a supported maximum denominator of 231.- Parameters:
value- Value to convert to a fraction.maxDenominator- Maximum allowed value for denominator.- Returns:
- a new instance.
- Throws:
IllegalArgumentException- if the givenvalueis NaN or infinite ormaxDenominatoris zero.ArithmeticException- if the continued fraction failed to converge.
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of
public static Fraction of(int num)
Create a fraction given the numerator. The denominator is1.- Parameters:
num- Numerator.- Returns:
- a new instance.
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of
public static Fraction of(int num, int den)
Create a fraction given the numerator and denominator. The fraction is reduced to lowest terms.- Parameters:
num- Numerator.den- Denominator.- Returns:
- a new instance.
- Throws:
ArithmeticException- if the denominator iszero.
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parse
public static Fraction parse(String s)
Returns aFractioninstance representing the specified strings.If
sisnull, then aNullPointerExceptionis thrown.The string must be in a format compatible with that produced by
Fraction.toString(). The format expects an integer optionally followed by a'/'character and and second integer. Leading and trailing spaces are allowed around each numeric part. Each numeric part is parsed usingInteger.parseInt(String). The parts are interpreted as the numerator and optional denominator of the fraction. If absent the denominator is assumed to be "1".Examples of valid strings and the equivalent
Fractionare shown below:"0" = Fraction.of(0) "42" = Fraction.of(42) "0 / 1" = Fraction.of(0, 1) "1 / 3" = Fraction.of(1, 3) "-4 / 13" = Fraction.of(-4, 13)
Note: The fraction is returned in reduced form and the numerator and denominator may not match the values in the input string. For this reason the result of
Fraction.parse(s).toString().equals(s)may not betrue.- Parameters:
s- String representation.- Returns:
- an instance.
- Throws:
NullPointerException- if the string is null.NumberFormatException- if the string does not contain a parsable fraction.- See Also:
Integer.parseInt(String),toString()
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one
public Fraction one()
- Specified by:
onein interfaceMultiplication<Fraction>
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isOne
public boolean isOne()
- Specified by:
isOnein interfaceMultiplication<Fraction>
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getNumerator
public int getNumerator()
Access the numerator as anint.- Returns:
- the numerator as an
int.
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getDenominator
public int getDenominator()
Access the denominator as anint.- Returns:
- the denominator as an
int.
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signum
public int signum()
Retrieves the sign of this fraction.- Returns:
- -1 if the value is strictly negative, 1 if it is strictly positive, 0 if it is 0.
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reciprocal
public Fraction reciprocal()
Raises an exception if the fraction is equal to zero.
- Specified by:
reciprocalin interfaceMultiplication<Fraction>- Throws:
ArithmeticException- if the current numerator iszero
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doubleValue
public double doubleValue()
Returns thedoublevalue closest to this fraction. This calculates the fraction as numerator divided by denominator.- Specified by:
doubleValuein classNumber- Returns:
- the fraction as a
double.
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floatValue
public float floatValue()
Returns thefloatvalue closest to this fraction. This calculates the fraction as numerator divided by denominator.- Specified by:
floatValuein classNumber- Returns:
- the fraction as a
float.
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intValue
public int intValue()
Returns the whole number part of the fraction.
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longValue
public long longValue()
Returns the whole number part of the fraction.
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add
public Fraction add(int value)
Adds the specifiedvalueto this fraction, returning the result in reduced form.- Parameters:
value- Value to add.- Returns:
this + value.- Throws:
ArithmeticException- if the resulting numerator cannot be represented in anint.
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add
public Fraction add(Fraction value)
Adds the specifiedvalueto this fraction, returning the result in reduced form.- Specified by:
addin interfaceAddition<Fraction>- Parameters:
value- Value to add.- Returns:
this + value.- Throws:
ArithmeticException- if the resulting numerator or denominator cannot be represented in anint.
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subtract
public Fraction subtract(int value)
Subtracts the specifiedvaluefrom this fraction, returning the result in reduced form.- Parameters:
value- Value to subtract.- Returns:
this - value.- Throws:
ArithmeticException- if the resulting numerator cannot be represented in anint.
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subtract
public Fraction subtract(Fraction value)
Subtracts the specifiedvaluefrom this fraction, returning the result in reduced form.- Specified by:
subtractin interfaceNativeOperators<Fraction>- Parameters:
value- Value to subtract.- Returns:
this - value.- Throws:
ArithmeticException- if the resulting numerator or denominator cannot be represented in anint.
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multiply
public Fraction multiply(int value)
Multiply this fraction by the passedvalue, returning the result in reduced form.- Specified by:
multiplyin interfaceNativeOperators<Fraction>- Parameters:
value- Value to multiply by.- Returns:
this * value.- Throws:
ArithmeticException- if the resulting numerator cannot be represented in anint.
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multiply
public Fraction multiply(Fraction value)
Multiply this fraction by the passedvalue, returning the result in reduced form.- Specified by:
multiplyin interfaceMultiplication<Fraction>- Parameters:
value- Value to multiply by.- Returns:
this * value.- Throws:
ArithmeticException- if the resulting numerator or denominator cannot be represented in anint.
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divide
public Fraction divide(int value)
Divide this fraction by the passedvalue, returning the result in reduced form.- Parameters:
value- Value to divide by- Returns:
this / value.- Throws:
ArithmeticException- if the value to divide by is zero or if the resulting numerator or denominator cannot be represented by anint.
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divide
public Fraction divide(Fraction value)
Divide this fraction by the passedvalue, returning the result in reduced form.- Specified by:
dividein interfaceNativeOperators<Fraction>- Parameters:
value- Value to divide by- Returns:
this / value.- Throws:
ArithmeticException- if the value to divide by is zero or if the resulting numerator or denominator cannot be represented by anint.
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pow
public Fraction pow(int exponent)
Returns aFractionwhose value isthisexponent, returning the result in reduced form.- Specified by:
powin interfaceNativeOperators<Fraction>- Parameters:
exponent- exponent to which thisFractionis to be raised.- Returns:
thisexponent.- Throws:
ArithmeticException- if the intermediate result would overflow.
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toString
public String toString()
Returns theStringrepresenting this fraction. Uses:"0"ifnumeratoris zero."numerator"ifdenominatoris one."numerator / denominator"for all other cases.
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compareTo
public int compareTo(Fraction other)
Compares this object with the specified object for order using the signed magnitude.- Specified by:
compareToin interfaceComparable<Fraction>- Parameters:
other-- Returns:
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equals
public boolean equals(Object other)
Test for equality with another object. If the other object is aFractionthen a comparison is made of the sign and magnitude; otherwisefalseis returned.
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