All Implemented Interfaces:

Comparable<MyFractionAlgebra>, JxnCloneableAlgebra
```
public class MyFractionAlgebra
extends Object
implements JxnCloneableAlgebra, Comparable<MyFractionAlgebra>
```
Simple implementation of a fraction algebra (example of a user defined algebra).
Stores numerator and denominator with int precision. Allows mixed operations with int and double.
For a may be more elaborate implementation see Commons Math → BigFraction

See Also:

user defined algebra

Field Summary

Fields
Modifier and Type	Field	Description
`protected int`	`denominator`
`protected boolean`	`exact`	Records if the fraction representation with int numerator and denomonator is exact or an approximation.
`protected int`	`numerator`

Constructor Summary

Constructors
Constructor	Description
`MyFractionAlgebra(double x)`	Finds a fraction that represents `x`, using the continued fraction algorithm.
`MyFractionAlgebra(int numerator)`	Equivalent to `new MyFractionAlgebra( numerator, 1 )`.
`MyFractionAlgebra(int numerator, int denominator)`	Constructs a new Fraction object.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`MyFractionAlgebra`	`add(MyFractionAlgebra opnd)`	Adds `opnd` to this.
`JxnCloneableAlgebra`	`cloneThis()`	Note: `MyFractionAlgebra` implements `JxnCloneableAlgebra` only for demonstration.
`int`	`compareTo(MyFractionAlgebra other)`	Returns -1 if `this < other`, +1 if `other > this`, else 0.
`double`	`doubleValue()`	Returns this fraction as double.
`boolean`	`equals(Object other)`	Fractions are equal, if both numerator and denominator are equal.
`static int`	`gcd(int m, int n)`	Returns the greatest common divisor (gcd) of `m` and `n`.
`int`	`getDenominator()`	Returns the internally stored denominator.
`int`	`getNumerator()`	Returns the internally stored numerator.
`MyFractionAlgebra`	`inv()`	Replaces this by its reciprocal.
`boolean`	`isExact()`	Returns, if the fraction (with int numerator and denominator) is exact (otherwise it is an approximation).
`static void`	`main(String[] args)`	Test.
`MyFractionAlgebra`	`mul(MyFractionAlgebra opnd)`	(Post)Multiplies this by `opnd`.
`MyFractionAlgebra`	`pow(int exponent)`	Replaces this by its power of `exponent`.
`protected int`	`power(int base, int exponent)`	power.
`protected void`	`reduce()`	Reduces the fraction: devides numerator and denominator by their greatest common divisor.
`MyFractionAlgebra`	`setExact(boolean exact)`	Declares that this fraction instance is considered exact.
`String`	`toString()`	Returns a string representation of the fraction.

Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - numerator
```
protected int numerator
```
  - denominator
```
protected int denominator
```
  - exact
```
protected boolean exact
```
    Records if the fraction representation with int numerator and denomonator is exact or an approximation. Is internally changed, if during calculations intermedeate results cannot be exactly represented with int numerator and denominator.
    
    See Also:
    
    toString()
- Constructor Detail
  - MyFractionAlgebra
```
public MyFractionAlgebra(int numerator,
                         int denominator)
```
    Constructs a new Fraction object.
  - MyFractionAlgebra
```
public MyFractionAlgebra(int numerator)
```
    Equivalent to new MyFractionAlgebra( numerator, 1 ).
    Required for mixed operations: int op fraction, fraction op int
  - MyFractionAlgebra
```
public MyFractionAlgebra(double x)
```
    Finds a fraction that represents x, using the continued fraction algorithm.
    Required for mixed operations: double op fraction, fraction op double.
    
    See Also:
    
    continued fraction
- Method Detail
  - getNumerator
```
public int getNumerator()
```
    Returns the internally stored numerator.
  - getDenominator
```
public int getDenominator()
```
    Returns the internally stored denominator.
  - isExact
```
public boolean isExact()
```
    Returns, if the fraction (with int numerator and denominator) is exact (otherwise it is an approximation).
    
    See Also:
    
    exact
  - setExact
```
public MyFractionAlgebra setExact(boolean exact)
```
    Declares that this fraction instance is considered exact.
    
    Returns:
    
    this
    
    See Also:
    
    exact
  - doubleValue
```
public double doubleValue()
```
    Returns this fraction as double.
  - cloneThis
```
public JxnCloneableAlgebra cloneThis()
```
    Note: MyFractionAlgebra implements JxnCloneableAlgebra only for demonstration. As MyFractionAlgebra has only 2 int members numerator and denominator it should better be implemented as immutable like java.math.BigInteger or Commons Math → BigFraction .
    
    Description copied from interface: JxnCloneableAlgebra
    Called internally. Required to avoid overwriting the left side operand opndLeft in opndLeft op opndRght, if op is implemented as opndLeft.op(opndRght) and the instance method op modifies the instance.
    
    Specified by:
    
    cloneThis in interface JxnCloneableAlgebra
    
    Returns:
    
    copy of this instance
  - add
```
public MyFractionAlgebra add(MyFractionAlgebra opnd)
```
    Adds opnd to this.
    
    Returns:
    
    this
  - mul
```
public MyFractionAlgebra mul(MyFractionAlgebra opnd)
```
    (Post)Multiplies this by opnd.
    
    Returns:
    
    this
  - inv
```
public MyFractionAlgebra inv()
```
    Replaces this by its reciprocal.
    
    Returns:
    
    this
  - pow
```
public MyFractionAlgebra pow(int exponent)
```
    Replaces this by its power of exponent.
    
    Returns:
    
    this
  - equals
```
public boolean equals(Object other)
```
    Fractions are equal, if both numerator and denominator are equal.
    (the exactness-information is not required to be equal)
    
    Overrides:
    
    equals in class Object
  - compareTo
```
public int compareTo(MyFractionAlgebra other)
```
    Returns -1 if this < other, +1 if other > this, else 0.
    
    Specified by:
    
    compareTo in interface Comparable<MyFractionAlgebra>
  - toString
```
public String toString()
```
    Returns a string representation of the fraction.
    
    Shows the fraction as "numerator / denominator = double-value", if int valued numerator and denominator allow an exact representation of the fraction, e.g. "1 / 8 = 0.125". However, if the fraction is an approximation, it is formatted as "double-value ~ numerator / denominator" e.g. "0.3 ~ 3 / 10" (there is no exact binary representation of the decimal 0.3).
    Note the difference:
    f1 = @MyFractionAlgebra( 3, 10 ) ! exact fraction = 3 / 10 = 0.3 (MyFractionAlgebra) f2 = @MyFractionAlgebra( 0.3 ) ! approximation of the double 0.3 = 0.3 ~ 3 / 10 (MyFractionAlgebra)
    The resulting fraction instances f1 and f2 are equal, but only f1 considers itself exact. A Calculation with fraction instances transfers the exactness-information to its result.
    Overrides:
    
    toString in class Object
    
    See Also:
    
    exact
  - gcd
```
public static int gcd(int m,
                      int n)
```
    Returns the greatest common divisor (gcd) of m and n.
  - reduce
```
protected void reduce()
```
    Reduces the fraction: devides numerator and denominator by their greatest common divisor.
  - power
```
protected int power(int base,
                    int exponent)
```
    power.
    
    Parameters:
    
    exponent - must be >= 0
  - main
```
public static void main(String[] args)
```
    Test.

Class MyFractionAlgebra

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

numerator

denominator

exact

Constructor Detail

MyFractionAlgebra

MyFractionAlgebra

MyFractionAlgebra

Method Detail

getNumerator

getDenominator

isExact

setExact

doubleValue

cloneThis

add

mul

inv

pow

equals

compareTo

toString

gcd

reduce

power

main