Ruby/Number/Rational Numbers
Материал из Wiki.crossplatform.ru
Add two rational number up
#!/usr/bin/env ruby require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat + 1/4 # => 1/2
Comparable operator on rational numbers
#!/usr/bin/env ruby require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat <=> 1/4 # => 0 rat <=> 1/8 # => 1 rat <=> 1/2 # => -1
Compare two rational numbers
#!/usr/bin/env ruby require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat == 1/8 # => false -- equality rat == 1/4 # => true
Create a rational number
#!/usr/bin/env ruby require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms
Divide two rational numbers
#!/usr/bin/env ruby require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat / 2 # => 1/8 -- divide
how to add (+), subtract (-), multiply (*), and divide (/) fractions;
require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat + Rational(1/4) # => 1/2 -- add rat + 1/4 # => 1/2 rat - Rational(1/8) # => 1/8 -- subtract rat - 1/8 # => 1/8 rat * 3 # => 3/4 -- multiply rat / 2 # => 1/8 -- divide
how to create a fraction;
require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms
how to perform modulo (%), power (**), and equality (== or <=>);
require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat % Rational(1/2) # => 1/4 -- modulo or remainder rat**2 # => 1/16 -- exponent or power rat == 1/8 # => false -- equality rat == 1/4 # => true rat <=> 1/4 # => 0 rat <=> 1/8 # => 1 rat <=> 1/2 # => -1
how to produce a string or a float representation of a fraction (inspect).
require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat.inspect # => "1/4" rat.to_s # => "1/4" rat.to_f # => 0.25 p rat # => 1/4
Inspect a rational number
#!/usr/bin/env ruby require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat.inspect # => "1/4"
Modulo two rational numbers
#!/usr/bin/env ruby require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat % Rational(1/2) # => 1/4 -- modulo or remainder
Multiply two rational numbers
#!/usr/bin/env ruby require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat * 3 # => 3/4 -- multiply
Power a rational number
#!/usr/bin/env ruby require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat**2 # => 1/16 -- exponent or power
Rational Numbers
A rational number is a number that can be expressed as a fraction of integers. Ruby supports the use of rational numbers via the Rational class. To use the Rational class, you must require it in the program. You create a rational number with the Rational method. Rational expects you to use integers, by the way. It will generate errors if you use floats.
Rational number without using Rational class
#!/usr/bin/env ruby require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat - 1/8 # => 1/8
Subtract one number from another
#!/usr/bin/env ruby require "rational" require "mathn" rat = Rational(25/100) # => 1/4 -- lowest terms rat - Rational(1/8) # => 1/8 -- subtract
