Package org.uncommons.maths.number
Class Rational
- java.lang.Object
-
- java.lang.Number
-
- org.uncommons.maths.number.Rational
-
- All Implemented Interfaces:
java.io.Serializable
,java.lang.Comparable<Rational>
public final class Rational extends java.lang.Number implements java.lang.Comparable<Rational>
Immutable value object for representing a rational number (or vulgar fraction). Instances of this class provide a way to perform arithmetic on fractional values without loss of precision. This implementation automatically simplifies fractions (3/6 is stored as 1/2). The implementation also requires that the denominator is positive. The numerator may be negative.- Since:
- 1.2
- See Also:
- Serialized Form
-
-
Field Summary
Fields Modifier and Type Field Description private long
denominator
static Rational
HALF
Convenient constant representing a value of a half (1/2 as a rational).private long
numerator
static Rational
ONE
Convenient constant representing a value of one (1/1 as a rational).static Rational
QUARTER
Convenient constant representing a value of a quarter (1/4 as a rational).static Rational
THIRD
Convenient constant representing a value of a third (1/3 as a rational).static Rational
THREE_QUARTERS
Convenient constant representing a value of three quarters (3/4 as a rational).static Rational
TWO_THIRDS
Convenient constant representing a value of two thirds (2/3 as a rational).static Rational
ZERO
Convenient constant representing a value of zero (0/1 as a rational).
-
Constructor Summary
Constructors Constructor Description Rational(long value)
Creates a rational value equivalent to the specified integer value.Rational(long numerator, long denominator)
Creates a vulgar fraction with the specified numerator and denominator.Rational(java.math.BigDecimal value)
Creates a rational value equivalent to the specified decimal value.
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description Rational
add(Rational value)
Add the specified value to this value and return the result as a new object (also a rational).int
compareTo(Rational other)
Compares this value with the specified object for order.Rational
divide(Rational value)
Divide this rational by the specified value and return the result as a new object (also a Rational).double
doubleValue()
Returns the result of dividing the numerator by the denominator.boolean
equals(java.lang.Object other)
Determines whether this rational value is equal to some other object.float
floatValue()
Returns the result of dividing the numerator by the denominator.long
getDenominator()
Returns the denominator (divisor) of the fraction.long
getNumerator()
Returns the numerator of the fraction.int
hashCode()
Over-ridden to be consistent withequals(Object)
.int
intValue()
Returns the integer equivalent of this rational number.long
longValue()
Returns the integer equivalent of this rational number as a long.Rational
multiply(Rational value)
Multiply this rational by the specified value and return the result as a new object (also a Rational).Rational
subtract(Rational value)
Subtract the specified value from this value and return the result as a new object (also a rational).java.lang.String
toString()
Returns a String representation of the rational number, expressed as a vulgar fraction (i.e.
-
-
-
Field Detail
-
ZERO
public static final Rational ZERO
Convenient constant representing a value of zero (0/1 as a rational).
-
QUARTER
public static final Rational QUARTER
Convenient constant representing a value of a quarter (1/4 as a rational).
-
THIRD
public static final Rational THIRD
Convenient constant representing a value of a third (1/3 as a rational).
-
HALF
public static final Rational HALF
Convenient constant representing a value of a half (1/2 as a rational).
-
TWO_THIRDS
public static final Rational TWO_THIRDS
Convenient constant representing a value of two thirds (2/3 as a rational).
-
THREE_QUARTERS
public static final Rational THREE_QUARTERS
Convenient constant representing a value of three quarters (3/4 as a rational).
-
ONE
public static final Rational ONE
Convenient constant representing a value of one (1/1 as a rational).
-
numerator
private final long numerator
-
denominator
private final long denominator
-
-
Constructor Detail
-
Rational
public Rational(long numerator, long denominator)
Creates a vulgar fraction with the specified numerator and denominator.- Parameters:
numerator
- The fraction's numerator (may be negative).denominator
- The fraction's denominator (must be greater than or equal to 1).
-
Rational
public Rational(long value)
Creates a rational value equivalent to the specified integer value.- Parameters:
value
- The value of this rational as an integer.
-
Rational
public Rational(java.math.BigDecimal value)
Creates a rational value equivalent to the specified decimal value.- Parameters:
value
- The value of this rational as a fractional decimal.- Throws:
java.lang.ArithmeticException
- If the BigDecimal value is too large to be represented as a Rational.
-
-
Method Detail
-
getNumerator
public long getNumerator()
Returns the numerator of the fraction.- Returns:
- The numerator.
-
getDenominator
public long getDenominator()
Returns the denominator (divisor) of the fraction.- Returns:
- The denominator.
-
add
public Rational add(Rational value)
Add the specified value to this value and return the result as a new object (also a rational). If the two values have different denominators, they will first be converted so that they have common denominators.- Parameters:
value
- The value to add to this rational.- Returns:
- A new rational value that is the sum of this value and the specified value.
-
subtract
public Rational subtract(Rational value)
Subtract the specified value from this value and return the result as a new object (also a rational). If the two values have different denominators, they will first be converted so that they have common denominators.- Parameters:
value
- The value to subtract from this rational.- Returns:
- A new rational value that is the result of subtracting the specified value from this value.
-
multiply
public Rational multiply(Rational value)
Multiply this rational by the specified value and return the result as a new object (also a Rational).- Parameters:
value
- The amount to multiply by.- Returns:
- A new rational value that is the result of multiplying this value by the specified value.
-
divide
public Rational divide(Rational value)
Divide this rational by the specified value and return the result as a new object (also a Rational).- Parameters:
value
- The amount to divide by.- Returns:
- A new rational value that is the result of dividing this value by the specified value.
-
intValue
public int intValue()
Returns the integer equivalent of this rational number. If there is no exact integer representation, it returns the closest integer that is lower than the rational value (effectively the truncated version of callingdoubleValue()
).- Specified by:
intValue
in classjava.lang.Number
- Returns:
- The (truncated) integer value of this rational.
-
longValue
public long longValue()
Returns the integer equivalent of this rational number as a long. If there is no exact integer representation, it returns the closest long that is lower than the rational value (effectively the truncated version of callingdoubleValue()
).- Specified by:
longValue
in classjava.lang.Number
- Returns:
- The (truncated) long value of this rational.
-
floatValue
public float floatValue()
Returns the result of dividing the numerator by the denominator. Will result in a loss of precision for fractions that have no exact float representation.- Specified by:
floatValue
in classjava.lang.Number
- Returns:
- The closest double-precision floating point equivalent of the fraction represented by this object.
-
doubleValue
public double doubleValue()
Returns the result of dividing the numerator by the denominator. Will result in a loss of precision for fractions that have no exact double representation.- Specified by:
doubleValue
in classjava.lang.Number
- Returns:
- The closest double-precision floating point equivalent of the fraction represented by this object.
-
equals
public boolean equals(java.lang.Object other)
Determines whether this rational value is equal to some other object. To be considered equal the other object must also be a Rational object with an indentical numerator and denominator.- Overrides:
equals
in classjava.lang.Object
- Parameters:
other
- The object to compare against.- Returns:
- True if the objects are equal, false otherwise.
-
hashCode
public int hashCode()
Over-ridden to be consistent withequals(Object)
.- Overrides:
hashCode
in classjava.lang.Object
- Returns:
- The hash code value.
-
toString
public java.lang.String toString()
Returns a String representation of the rational number, expressed as a vulgar fraction (i.e. 1 and 1/3 is shown as 4/3). If the rational is equal to an integer, the value is simply displayed as that integer with no fractional part (i.e. 2/1 is shown as 2).- Overrides:
toString
in classjava.lang.Object
- Returns:
- A string representation of this rational value.
-
compareTo
public int compareTo(Rational other)
Compares this value with the specified object for order. Returns a negative integer, zero, or a positive integer as this value is less than, equal to, or greater than the specified value.- Specified by:
compareTo
in interfacejava.lang.Comparable<Rational>
- Parameters:
other
- Another Rational value.- Returns:
- A negative integer, zero, or a positive integer as this value is less than, equal to, or greater than the specified value.
-
-