Module: Enumerable

Defined in:
lib/util/enum_extensions.rb

Instance Method Summary collapse

Instance Method Details

#mean ⇒ Object Also known as: average 



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# File 'lib/util/enum_extensions.rb', line 7

def mean
  self.sum/self.length.to_f
end

#sample_variance ⇒ Object 



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# File 'lib/util/enum_extensions.rb', line 11

def sample_variance
  m = self.mean
  sum = self.inject(0){|accum, i| accum + (i-m)**2}
  sum/(self.length - 1).to_f
end

#standard_deviation ⇒ Object 



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# File 'lib/util/enum_extensions.rb', line 16

def standard_deviation
  Math.sqrt(self.sample_variance)
end

#sum ⇒ Object

Thanks StackOverflow users! stackoverflow.com/questions/7749568/how-can-i-do-standard-deviation-in-ruby



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# File 'lib/util/enum_extensions.rb', line 4

def sum
  self.inject(:+)
end