- Inheritance
- < Object
Rational implements a rational class for numbers.
A rational number is a number that can be expressed as a fraction p/q where p and q are integers and q != 0. A rational number p/q is said to have numerator p and denominator q. Numbers that are not rational are called irrational numbers. (mathworld.wolfram.com/RationalNumber.html)
To create a Rational Number:
Rational(a,b) # -> a/b Rational.new!(a,b) # -> a/b
Examples:
Rational(5,6) # -> 5/6 Rational(5) # -> 5/1
Rational numbers are reduced to their lowest terms:
Rational(6,10) # -> 3/5
But not if you use the unusual method "new!":
Rational.new!(6,10) # -> 6/10
Division by zero is obviously not allowed:
Rational(3,0) # -> ZeroDivisionError
Constants
| Name | Description | |
|---|---|---|
| Unify | = true |
Attributes
| Name | Visibility | R/W | Description |
|---|---|---|---|
| denominator | public | R | |
| numerator | public | R |
Aliases
| Method | Alias | Description |
|---|---|---|
| ** | → power! |
Methods
Class
| Visibility | Signature |
|---|---|
| public | new (num, den) |
| public | new! (num, den = 1) |
| public | reduce (num, den = 1) |
Instance
| Visibility | Signature |
|---|---|
| public | % (other) |
| public | * (a) |
| public | ** (other) |
| public | ** (other) |
| public | + (a) |
| public | - (a) |
| public | / (a) |
| public | <=> (other) |
| public | == (other) |
| public | abs () |
| public | ceil () |
| public | coerce (other) |
| public | div (other) |
| public | divmod (other) |
| public | floor () |
| public | hash () |
| public | inspect () |
| public | inspect () |
| public | power2 (other) |
| public | round () |
| public | to_f () |
| public | to_i () |
| public | to_r () |
| public | to_s () |
| public | truncate () |
Class Method Detail
new(num, den)
This method is actually private.
new!(num, den = 1)
Implements the constructor. This method does not reduce to lowest terms or check for division by zero. Therefore Rational() should be preferred in normal use.
reduce(num, den = 1)
Reduces the given numerator and denominator to their lowest terms. Use Rational() instead.
Instance Method Detail
%(other)
Returns the remainder when this value is divided by other.
Examples:
r = Rational(7,4) # -> Rational(7,4) r % Rational(1,2) # -> Rational(1,4) r % 1 # -> Rational(3,4) r % Rational(1,7) # -> Rational(1,28) r % 0.26 # -> 0.19
*(a)
Returns the product of this value and a.
Examples:
r = Rational(3,4) # -> Rational(3,4) r * 2 # -> Rational(3,2) r * 4 # -> Rational(3,1) r * 0.5 # -> 0.375 r * Rational(1,2) # -> Rational(3,8)
**(other)
**(other)
Returns this value raised to the given power.
Examples:
r = Rational(3,4) # -> Rational(3,4) r ** 2 # -> Rational(9,16) r ** 2.0 # -> 0.5625 r ** Rational(1,2) # -> 0.866025403784439
+(a)
Returns the addition of this value and a.
Examples:
r = Rational(3,4) # -> Rational(3,4) r + 1 # -> Rational(7,4) r + 0.5 # -> 1.25
-(a)
Returns the difference of this value and a. subtracted.
Examples:
r = Rational(3,4) # -> Rational(3,4) r - 1 # -> Rational(-1,4) r - 0.5 # -> 0.25
/(a)
Returns the quotient of this value and a.
r = Rational(3,4) # -> Rational(3,4) r / 2 # -> Rational(3,8) r / 2.0 # -> 0.375 r / Rational(1,2) # -> Rational(3,2)
<=>(other)
Standard comparison operator.
==(other)
Returns true iff this value is numerically equal to other.
But beware:
Rational(1,2) == Rational(4,8) # -> true Rational(1,2) == Rational.new!(4,8) # -> false
Don‘t use Rational.new!
abs()
Returns the absolute value.
ceil()
coerce(other)
div(other)
divmod(other)
Returns the quotient and remainder.
Examples:
r = Rational(7,4) # -> Rational(7,4) r.divmod Rational(1,2) # -> [3, Rational(1,4)]
floor()
Converts the rational to an Integer. Not the nearest integer, the truncated integer. Study the following example carefully:
Rational(+7,4).to_i # -> 1 Rational(-7,4).to_i # -> -1 (-1.75).to_i # -> -1
In other words:
Rational(-7,4) == -1.75 # -> true Rational(-7,4).to_i == (-1.75).to_i # -> true
hash()
Returns a hash code for the object.
inspect()
inspect()
Returns a reconstructable string representation:
Rational(5,8).inspect # -> "Rational(5, 8)"
power2(other)
round()
to_f()
Converts the rational to a Float.
to_i()
Alias for truncate
to_r()
Returns self.
to_s()
Returns a string representation of the rational number.
Example:
Rational(3,4).to_s # "3/4" Rational(8).to_s # "8"