Module: Enumerable

Defined in:
lib/ruby-util/enumerable.rb

Instance Method Summary collapse

Instance Method Details

#arithmetic_mean ⇒ Object Also known as: average

Calculates arithmectic mean of all elements in the collection.



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# File 'lib/ruby-util/enumerable.rb', line 30

def arithmetic_mean
  size > 0 ? sum.to_f / size : 0
end

#geometric_mean ⇒ Object

Calculates geometric mean of all elements in the collection.



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# File 'lib/ruby-util/enumerable.rb', line 37

def geometric_mean
  size > 0 ? Math.root(product, size) : 0
end

#harmonic_mean ⇒ Object

Calculates harmonic mean of all elements in the collection.



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# File 'lib/ruby-util/enumerable.rb', line 42

def harmonic_mean
  size > 0 ? size / reverse_sum : 0
end

#inversed_sum ⇒ Object

Calculates inversed sum of the collection.



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# File 'lib/ruby-util/enumerable.rb', line 8

def inversed_sum
  1.0 / sum
end

#product ⇒ Object Also known as: multiply

Multiplicates all elements of the collection.



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# File 'lib/ruby-util/enumerable.rb', line 23

def product
  inject(nil) { |mul, x| mul ? mul * x : x }
end

#reverse_sum ⇒ Object

Calculates reverse sum of the collection.



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# File 'lib/ruby-util/enumerable.rb', line 13

def reverse_sum
  sum.to_i > 0 ? inject(nil) { |sum, x| sum ? sum + 1.0 / x : 1.0 / x } : 0
end

#root_mean_square ⇒ Object

Calculates root mean square of all elements in the collection.



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# File 'lib/ruby-util/enumerable.rb', line 47

def root_mean_square
  size > 0 ? Math.sqrt(square_root_sum / size) : 0
end

#square_root_sum ⇒ Object

Calculates square root sum of the collection.



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# File 'lib/ruby-util/enumerable.rb', line 18

def square_root_sum
  inject(nil) { |sum, x| sum ? sum + x ** 2 : x ** 2 }
end

#sum ⇒ Object

Calculates sum of the collection.



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# File 'lib/ruby-util/enumerable.rb', line 3

def sum
  inject(nil) { |sum, x| sum ? sum + x : x }
end