Class Fraction
- All Implemented Interfaces:
Serializable
,Comparable<Fraction>
,FieldElement<Fraction>
- Since:
- 1.1
- See Also:
-
Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final double
The default epsilon used for convergence.private final int
The denominator.static final Fraction
A fraction representing "4/5".static final Fraction
A fraction representing "-1 / 1".private final int
The numerator.static final Fraction
A fraction representing "1".static final Fraction
A fraction representing "1/5".static final Fraction
A fraction representing "1/2".static final Fraction
A fraction representing "1/4".static final Fraction
A fraction representing "1/3".private static final long
Serializable version identifierstatic final Fraction
A fraction representing "3/5".static final Fraction
A fraction representing "3/4".static final Fraction
A fraction representing "2 / 1".static final Fraction
A fraction representing "2/5".static final Fraction
A fraction representing "2/4".static final Fraction
A fraction representing "2/3".static final Fraction
A fraction representing "0". -
Constructor Summary
ConstructorsModifierConstructorDescriptionFraction
(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.private
Fraction
(double value, double epsilon, int maxDenominator, int maxIterations) Create a fraction given the double value and either the maximum error allowed or the maximum number of denominator digits.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 TypeMethodDescriptionabs()
Returns the absolute value of this fraction.add
(int i) Add an integer to the fraction.Adds the value of this fraction to another, returning the result in reduced form.private Fraction
Implement add and subtract using algorithm described in Knuth 4.5.1.int
Compares this object to another based on size.divide
(int i) Divide the fraction by an integer.Divide the value of this fraction by another.double
Gets the fraction as adouble
.boolean
Test for the equality of two fractions.float
Gets the fraction as afloat
.int
Access the denominator.getField()
Get theField
to which the instance belongs.int
Access the numerator.static Fraction
getReducedFraction
(int numerator, int denominator) Creates aFraction
instance with the 2 parts of a fraction Y/Z.int
hashCode()
Gets a hashCode for the fraction.int
intValue()
Gets the fraction as anint
.long
Gets the fraction as along
.multiply
(int i) Multiply the fraction by an integer.Multiplies the value of this fraction by another, returning the result in reduced form.negate()
Return the additive inverse of this fraction.double
Gets the fraction percentage as adouble
.Return the multiplicative inverse of this fraction.subtract
(int i) Subtract an integer from the fraction.Subtracts the value of another fraction from the value of this one, returning the result in reduced form.toString()
Returns theString
representing this fraction, ie "num / dem" or just "num" if the denominator is one.Methods inherited from class java.lang.Number
byteValue, shortValue
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Field Details
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TWO
A fraction representing "2 / 1". -
ONE
A fraction representing "1". -
ZERO
A fraction representing "0". -
FOUR_FIFTHS
A fraction representing "4/5". -
ONE_FIFTH
A fraction representing "1/5". -
ONE_HALF
A fraction representing "1/2". -
ONE_QUARTER
A fraction representing "1/4". -
ONE_THIRD
A fraction representing "1/3". -
THREE_FIFTHS
A fraction representing "3/5". -
THREE_QUARTERS
A fraction representing "3/4". -
TWO_FIFTHS
A fraction representing "2/5". -
TWO_QUARTERS
A fraction representing "2/4". -
TWO_THIRDS
A fraction representing "2/3". -
MINUS_ONE
A fraction representing "-1 / 1". -
serialVersionUID
private static final long serialVersionUIDSerializable version identifier- See Also:
-
DEFAULT_EPSILON
private static final double DEFAULT_EPSILONThe default epsilon used for convergence.- See Also:
-
denominator
private final int denominatorThe denominator. -
numerator
private final int numeratorThe numerator.
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-
Constructor Details
-
Fraction
Create a fraction given the double value.- Parameters:
value
- the double value to convert to a fraction.- Throws:
FractionConversionException
- if the continued fraction failed to converge.
-
Fraction
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 withinepsilon
ofvalue
, in absolute terms.maxIterations
- maximum number of convergents- Throws:
FractionConversionException
- if the continued fraction failed to converge.
-
Fraction
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:
FractionConversionException
- if the continued fraction failed to converge
-
Fraction
private Fraction(double value, double epsilon, int maxDenominator, int maxIterations) throws FractionConversionException Create a fraction given the double value and either the maximum error allowed or the maximum number of denominator digits.NOTE: This constructor is called with EITHER - a valid epsilon value and the maxDenominator set to Integer.MAX_VALUE (that way the maxDenominator has no effect). OR - a valid maxDenominator value and the epsilon value set to zero (that way epsilon only has effect if there is an exact match before the maxDenominator value is reached).
It has been done this way so that the same code can be (re)used for both scenarios. However this could be confusing to users if it were part of the public API and this constructor should therefore remain PRIVATE.
See JIRA issue ticket MATH-181 for more details: https://issues.apache.org/jira/browse/MATH-181- Parameters:
value
- the double value to convert to a fraction.epsilon
- maximum error allowed. The resulting fraction is withinepsilon
ofvalue
, in absolute terms.maxDenominator
- maximum denominator value allowed.maxIterations
- maximum number of convergents- Throws:
FractionConversionException
- 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.
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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:
MathArithmeticException
- if the denominator iszero
-
-
Method Details
-
abs
Returns the absolute value of this fraction.- Returns:
- the absolute value.
-
compareTo
Compares this object to another based on size.- Specified by:
compareTo
in interfaceComparable<Fraction>
- Parameters:
object
- the object to compare to- Returns:
- -1 if this is less than
object
, +1 if this is greater thanobject
, 0 if they are equal.
-
doubleValue
public double doubleValue()Gets the fraction as adouble
. This calculates the fraction as the numerator divided by denominator.- Specified by:
doubleValue
in classNumber
- Returns:
- the fraction as a
double
-
equals
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. -
floatValue
public float floatValue()Gets the fraction as afloat
. This calculates the fraction as the numerator divided by denominator.- Specified by:
floatValue
in classNumber
- 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.
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hashCode
public int hashCode()Gets a hashCode for the fraction. -
intValue
public int intValue()Gets the fraction as anint
. This returns the whole number part of the fraction. -
longValue
public long longValue()Gets the fraction as along
. This returns the whole number part of the fraction. -
negate
Return the additive inverse of this fraction.- Specified by:
negate
in interfaceFieldElement<Fraction>
- Returns:
- the negation of this fraction.
-
reciprocal
Return the multiplicative inverse of this fraction.- Specified by:
reciprocal
in interfaceFieldElement<Fraction>
- Returns:
- the reciprocal fraction
-
add
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 interfaceFieldElement<Fraction>
- Parameters:
fraction
- the fraction to add, must not benull
- Returns:
- a
Fraction
instance with the resulting values - Throws:
NullArgumentException
- if the fraction isnull
MathArithmeticException
- if the resulting numerator or denominator exceedsInteger.MAX_VALUE
-
add
Add an integer to the fraction.- Parameters:
i
- theinteger
to add.- Returns:
- this + i
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subtract
Subtracts the value of another fraction from the value of this one, returning the result in reduced form.
- Specified by:
subtract
in interfaceFieldElement<Fraction>
- Parameters:
fraction
- the fraction to subtract, must not benull
- Returns:
- a
Fraction
instance with the resulting values - Throws:
NullArgumentException
- if the fraction isnull
MathArithmeticException
- if the resulting numerator or denominator cannot be represented in anint
.
-
subtract
Subtract an integer from the fraction.- Parameters:
i
- theinteger
to subtract.- Returns:
- this - i
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addSub
Implement add and subtract using algorithm described in Knuth 4.5.1.- Parameters:
fraction
- the fraction to subtract, must not benull
isAdd
- true to add, false to subtract- Returns:
- a
Fraction
instance with the resulting values - Throws:
NullArgumentException
- if the fraction isnull
MathArithmeticException
- if the resulting numerator or denominator cannot be represented in anint
.
-
multiply
Multiplies the value of this fraction by another, returning the result in reduced form.
- Specified by:
multiply
in interfaceFieldElement<Fraction>
- Parameters:
fraction
- the fraction to multiply by, must not benull
- Returns:
- a
Fraction
instance with the resulting values - Throws:
NullArgumentException
- if the fraction isnull
MathArithmeticException
- if the resulting numerator or denominator exceedsInteger.MAX_VALUE
-
multiply
Multiply the fraction by an integer.- Specified by:
multiply
in interfaceFieldElement<Fraction>
- Parameters:
i
- theinteger
to multiply by.- Returns:
- this * i
-
divide
Divide the value of this fraction by another.
- Specified by:
divide
in interfaceFieldElement<Fraction>
- Parameters:
fraction
- the fraction to divide by, must not benull
- Returns:
- a
Fraction
instance with the resulting values - Throws:
IllegalArgumentException
- if the fraction isnull
MathArithmeticException
- if the fraction to divide by is zeroMathArithmeticException
- if the resulting numerator or denominator exceedsInteger.MAX_VALUE
-
divide
Divide the fraction by an integer.- Parameters:
i
- theinteger
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
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:
MathArithmeticException
- if the denominator iszero
-
toString
Returns the
String
representing this fraction, ie "num / dem" or just "num" if the denominator is one. -
getField
Get theField
to which the instance belongs.- Specified by:
getField
in interfaceFieldElement<Fraction>
- Returns:
Field
to which the instance belongs
-