module Enumerable

Add methods to Enumerable, which makes them available to Array

mean() click to toggle source

mean of an array of numbers

# File lib/maths.rb, line 9
def mean
  return self.sum/self.length.to_f
end

sample_variance() click to toggle source

variance of an array of numbers

# File lib/maths.rb, line 14
def sample_variance
  mean=self.mean
  sum=self.inject(0){|acc,i|acc +(i-mean)**2}
  return(1/self.length.to_f*sum)
end

standard_deviation() click to toggle source

standard deviation of an array of numbers

# File lib/maths.rb, line 21
def standard_deviation
  return Math.sqrt(self.sample_variance)
end

sum() click to toggle source

sum of an array of numbers

# File lib/maths.rb, line 4
def sum
  return self.inject(0){|acc,i|acc +i}
end