Module: Enumerable

Defined in:
lib/indicators/calculations/helper.rb

Overview

Extra methods for mathematical calculations.

Instance Method Summary collapse

Instance Method Details

#mean ⇒ Object 



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# File 'lib/indicators/calculations/helper.rb', line 77

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

#sample_variance ⇒ Object 



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# File 'lib/indicators/calculations/helper.rb', line 81

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

#standard_deviation ⇒ Object 



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# File 'lib/indicators/calculations/helper.rb', line 87

def standard_deviation
  return Math.sqrt(self.sample_variance)
end

#sum ⇒ Object 



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# File 'lib/indicators/calculations/helper.rb', line 73

def sum
  return self.inject(0){|accum, i| accum + i }
end