org.hipparchus.fraction

Class Fraction

java.lang.Object

java.lang.Number

org.hipparchus.fraction.Fraction

All Implemented Interfaces:

Serializable, Comparable<Fraction>, FieldElement<Fraction>

public class Fraction
extends Number
implements FieldElement<Fraction>, Comparable<Fraction>, Serializable

Representation of a rational number.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Fraction.ConvergenceTest A test to determine if a series of fractions has converged.

Field Summary

Fields

Modifier and Type	Field and Description
static Fraction	FOUR_FIFTHS A fraction representing "4/5".
static Fraction	MINUS_ONE A fraction representing "-1 / 1".
static Fraction	ONE A fraction representing "1".
static Fraction	ONE_FIFTH A fraction representing "1/5".
static Fraction	ONE_HALF A fraction representing "1/2".
static Fraction	ONE_QUARTER A fraction representing "1/4".
static Fraction	ONE_THIRD A fraction representing "1/3".
static Fraction	THREE_FIFTHS A fraction representing "3/5".
static Fraction	THREE_QUARTERS A fraction representing "3/4".
static Fraction	TWO A fraction representing "2 / 1".
static Fraction	TWO_FIFTHS A fraction representing "2/5".
static Fraction	TWO_QUARTERS A fraction representing "2/4".
static Fraction	TWO_THIRDS A fraction representing "2/3".
static Fraction	ZERO A fraction representing "0".

Constructor Summary

Constructors

Constructor and Description
Fraction(double value) Create a fraction given the double value.
Fraction(double value, double epsilon, int maxIterations) Create a fraction given the double value and maximum error allowed.
Fraction(double value, int maxDenominator) Create a fraction given the double value and maximum denominator.
Fraction(int num) Create a fraction from an int.
Fraction(int num, int den) Create a fraction given the numerator and denominator.

Method Summary

Modifier and Type	Method and Description
Fraction	abs() Returns the absolute value of this fraction.
Fraction	add(Fraction fraction) Adds the value of this fraction to another, returning the result in reduced form.
Fraction	add(int i) Add an integer to the fraction.
int	compareTo(Fraction object) Compares this object to another based on size.
static Pair<Fraction,Boolean>	convergent(double value, int maxConvergents, Fraction.ConvergenceTest convergenceTest) Returns the last element of the series of convergent-steps to approximate the given value.
static Stream<Fraction>	convergents(double value, int maxConvergents) Generate a stream of convergents from a real number.
Fraction	divide(Fraction fraction) Divide the value of this fraction by another.
Fraction	divide(int i) Divide the fraction by an integer.
double	doubleValue() Gets the fraction as a double.
boolean	equals(Object other) Test for the equality of two fractions.
float	floatValue() Gets the fraction as a float.
int	getDenominator() Access the denominator.
FractionField	getField() Get the Field to which the instance belongs.
int	getNumerator() Access the numerator.
double	getReal() Get the real value of the number.
static Fraction	getReducedFraction(int numerator, int denominator) Creates a Fraction instance with the 2 parts of a fraction Y/Z.
int	hashCode() Gets a hashCode for the fraction.
int	intValue() Gets the fraction as an int.
boolean	isInteger() Check if a fraction is an integer.
long	longValue() Gets the fraction as a long.
Fraction	multiply(Fraction fraction) Multiplies the value of this fraction by another, returning the result in reduced form.
Fraction	multiply(int i) Multiply the fraction by an integer.
Fraction	negate() Return the additive inverse of this fraction.
double	percentageValue() Gets the fraction percentage as a double.
Fraction	reciprocal() Return the multiplicative inverse of this fraction.
int	signum() Returns the signum function of this fraction.
Fraction	subtract(Fraction fraction) Subtracts the value of another fraction from the value of this one, returning the result in reduced form.
Fraction	subtract(int i) Subtract an integer from the fraction.
String	toString() Returns the String representing this fraction, ie "num / dem" or just "num" if the denominator is one.

Methods inherited from class java.lang.Number

byteValue, shortValue

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.hipparchus.FieldElement

isZero

Field Detail

TWO

public static final Fraction TWO

A fraction representing "2 / 1".

ONE

public static final Fraction ONE

A fraction representing "1".

ZERO

public static final Fraction ZERO

A fraction representing "0".

FOUR_FIFTHS

public static final Fraction FOUR_FIFTHS

A fraction representing "4/5".

ONE_FIFTH

public static final Fraction ONE_FIFTH

A fraction representing "1/5".

ONE_HALF

public static final Fraction ONE_HALF

A fraction representing "1/2".

ONE_QUARTER

public static final Fraction ONE_QUARTER

A fraction representing "1/4".

ONE_THIRD

public static final Fraction ONE_THIRD

A fraction representing "1/3".

THREE_FIFTHS

public static final Fraction THREE_FIFTHS

A fraction representing "3/5".

THREE_QUARTERS

public static final Fraction THREE_QUARTERS

A fraction representing "3/4".

TWO_FIFTHS

public static final Fraction TWO_FIFTHS

A fraction representing "2/5".

TWO_QUARTERS

public static final Fraction TWO_QUARTERS

A fraction representing "2/4".

TWO_THIRDS

public static final Fraction TWO_THIRDS

A fraction representing "2/3".

MINUS_ONE

public static final Fraction MINUS_ONE

A fraction representing "-1 / 1".

Constructor Detail

Fraction

public Fraction(double value)
         throws MathIllegalStateException

Create a fraction given the double value.

Parameters:

value - the double value to convert to a fraction.

Throws:

MathIllegalStateException - if the continued fraction failed to converge.

Fraction

public Fraction(double value,
                double epsilon,
                int maxIterations)
         throws MathIllegalStateException

Create a fraction given the double value and maximum error allowed.

References:

• Continued Fraction equations (11) and (22)-(26)

Parameters:

value - the double value to convert to a fraction.

epsilon - maximum error allowed. The resulting fraction is within epsilon of value, in absolute terms.

maxIterations - maximum number of convergents

Throws:

MathIllegalStateException - if the continued fraction failed to converge.

Fraction

public Fraction(double value,
                int maxDenominator)
         throws MathIllegalStateException

Create a fraction given the double value and maximum denominator.

References:

• Continued Fraction equations (11) and (22)-(26)

Parameters:

value - the double value to convert to a fraction.

maxDenominator - The maximum allowed value for denominator

Throws:

MathIllegalStateException - if the continued fraction failed to converge

Fraction

public Fraction(int num)

Create a fraction from an int. The fraction is num / 1.

Parameters:

num - the numerator.

Fraction

public Fraction(int num,
                int den)

Create a fraction given the numerator and denominator. The fraction is reduced to lowest terms.

Parameters:

num - the numerator.

den - the denominator.

Throws:

MathRuntimeException - if the denominator is zero

Method Detail

convergents

public static Stream<Fraction> convergents(double value,
                                           int maxConvergents)

Generate a stream of convergents from a real number.

Parameters:

value - value to approximate

maxConvergents - maximum number of convergents.

Returns:

stream of Fraction convergents approximating value

Since:

2.1

convergent

public static Pair<Fraction,Boolean> convergent(double value,
                                                int maxConvergents,
                                                Fraction.ConvergenceTest convergenceTest)

Returns the last element of the series of convergent-steps to approximate the given value.

The series terminates either at the first step that satisfies the given convergenceTest or after at most maxConvergents elements. The returned Pair consists of that terminal Fraction and a Boolean that indicates if it satisfies the given convergence tests. If the returned pair's value is false the element at position maxConvergents was examined but failed to satisfy the convergenceTest. A caller can then decide to accept the result nevertheless or to discard it. This method is usually faster than convergents(double, int) if only the terminal element is of interest.

Parameters:

value - value to approximate

maxConvergents - maximum number of convergents to examine

convergenceTest - the test if the series has converged at a step

Returns:

the pair of last element of the series of convergents and a boolean indicating if that element satisfies the specified convergent test

getReal

public double getReal()

Get the real value of the number.

Specified by:

getReal in interface FieldElement<Fraction>

Returns:

real value

isInteger

public boolean isInteger()

Check if a fraction is an integer.

Returns:

true of fraction is an integer

signum

public int signum()

Returns the signum function of this fraction.

The return value is -1 if the specified value is negative; 0 if the specified value is zero; and 1 if the specified value is positive.

Returns:

the signum function of this fraction

Since:

1.7

abs

public Fraction abs()

Returns the absolute value of this fraction.

Returns:

the absolute value.

compareTo

public int compareTo(Fraction object)

Compares this object to another based on size.

Specified by:

compareTo in interface Comparable<Fraction>

Parameters:

object - the object to compare to

Returns:

-1 if this is less than object, +1 if this is greater than object, 0 if they are equal.

doubleValue

public double doubleValue()

Gets the fraction as a double. This calculates the fraction as the numerator divided by denominator.

Specified by:

doubleValue in class Number

Returns:

the fraction as a double

equals

public boolean equals(Object other)

Test for the equality of two fractions. If the lowest term numerator and denominators are the same for both fractions, the two fractions are considered to be equal.

Overrides:

equals in class Object

Parameters:

other - fraction to test for equality to this fraction

Returns:

true if two fractions are equal, false if object is null, not an instance of Fraction, or not equal to this fraction instance.

floatValue

public float floatValue()

Gets the fraction as a float. This calculates the fraction as the numerator divided by denominator.

Specified by:

floatValue in class Number

Returns:

the fraction as a float

getDenominator

public int getDenominator()

Access the denominator.

Returns:

the denominator.

getNumerator

public int getNumerator()

Access the numerator.

Returns:

the numerator.

hashCode

public int hashCode()

Gets a hashCode for the fraction.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object

intValue

public int intValue()

Gets the fraction as an int. This returns the whole number part of the fraction.

Specified by:

intValue in class Number

Returns:

the whole number fraction part

longValue

public long longValue()

Gets the fraction as a long. This returns the whole number part of the fraction.

Specified by:

longValue in class Number

Returns:

the whole number fraction part

negate

public Fraction negate()

Return the additive inverse of this fraction.

Specified by:

negate in interface FieldElement<Fraction>

Returns:

the negation of this fraction.

reciprocal

public Fraction reciprocal()

Return the multiplicative inverse of this fraction.

Specified by:

reciprocal in interface FieldElement<Fraction>

Returns:

the reciprocal fraction

add

public Fraction add(Fraction fraction)

Adds the value of this fraction to another, returning the result in reduced form. The algorithm follows Knuth, 4.5.1.

Specified by:

add in interface FieldElement<Fraction>

Parameters:

fraction - the fraction to add, must not be null

Returns:

a Fraction instance with the resulting values

Throws:

NullArgumentException - if the fraction is null

MathRuntimeException - if the resulting numerator or denominator exceeds Integer.MAX_VALUE

add

public Fraction add(int i)

Add an integer to the fraction.

Parameters:

i - the integer to add.

Returns:

this + i

subtract

public Fraction subtract(Fraction fraction)

Subtracts the value of another fraction from the value of this one, returning the result in reduced form.

Specified by:

subtract in interface FieldElement<Fraction>

Parameters:

fraction - the fraction to subtract, must not be null

Returns:

a Fraction instance with the resulting values

Throws:

NullArgumentException - if the fraction is null

MathRuntimeException - if the resulting numerator or denominator cannot be represented in an int.

subtract

public Fraction subtract(int i)

Subtract an integer from the fraction.

Parameters:

i - the integer to subtract.

Returns:

this - i

multiply

public Fraction multiply(Fraction fraction)

Multiplies the value of this fraction by another, returning the result in reduced form.

Specified by:

multiply in interface FieldElement<Fraction>

Parameters:

fraction - the fraction to multiply by, must not be null

Returns:

a Fraction instance with the resulting values

Throws:

NullArgumentException - if the fraction is null

MathRuntimeException - if the resulting numerator or denominator exceeds Integer.MAX_VALUE

multiply

public Fraction multiply(int i)

Multiply the fraction by an integer.

Specified by:

multiply in interface FieldElement<Fraction>

Parameters:

i - the integer to multiply by.

Returns:

this * i

divide

public Fraction divide(Fraction fraction)

Divide the value of this fraction by another.

Specified by:

divide in interface FieldElement<Fraction>

Parameters:

fraction - the fraction to divide by, must not be null

Returns:

a Fraction instance with the resulting values

Throws:

IllegalArgumentException - if the fraction is null

MathRuntimeException - if the fraction to divide by is zero

MathRuntimeException - if the resulting numerator or denominator exceeds Integer.MAX_VALUE

divide

public Fraction divide(int i)

Divide the fraction by an integer.

Parameters:

i - the integer to divide by.

Returns:

this * i

percentageValue

public double percentageValue()

Gets the fraction percentage as a double. This calculates the fraction as the numerator divided by denominator multiplied by 100.

Returns:

the fraction percentage as a double.

getReducedFraction

public static Fraction getReducedFraction(int numerator,
                                          int denominator)

Creates a Fraction instance with the 2 parts of a fraction Y/Z.

Any negative signs are resolved to be on the numerator.

Parameters:

numerator - the numerator, for example the three in 'three sevenths'

denominator - the denominator, for example the seven in 'three sevenths'

Returns:

a new fraction instance, with the numerator and denominator reduced

Throws:

MathRuntimeException - if the denominator is zero

toString

public String toString()

Returns the String representing this fraction, ie "num / dem" or just "num" if the denominator is one.

Overrides:

toString in class Object

Returns:

a string representation of the fraction.

See Also:

Object.toString()

getField

public FractionField getField()

Get the Field to which the instance belongs.

Specified by:

getField in interface FieldElement<Fraction>

Returns:

Field to which the instance belongs