module Enumerable - standard-deviation-0.1.1 Documentation

max_standard_deviation() click to toggle source

# File lib/enumerable/standard_deviation/standard_deviation.rb, line 21
def max_standard_deviation
  mean + standard_deviation
end

Also aliased as: max_std_dev

max_std_dev()

Alias for: max_standard_deviation

mean() click to toggle source

# File lib/enumerable/standard_deviation/standard_deviation.rb, line 6
def mean
  sum / length.to_f
end

min_standard_deviation() click to toggle source

# File lib/enumerable/standard_deviation/standard_deviation.rb, line 26
def min_standard_deviation
  mean - standard_deviation
end

Also aliased as: min_std_dev

min_std_dev()

Alias for: min_standard_deviation

sample_variance() click to toggle source

# File lib/enumerable/standard_deviation/standard_deviation.rb, line 10
def sample_variance
  m = mean
  sum = inject(0){|sum, i| sum + (i - m) ** 2 }
  sum / (length - 1).to_f
end

standard_deviation() click to toggle source

# File lib/enumerable/standard_deviation/standard_deviation.rb, line 16
def standard_deviation
  Math.sqrt(sample_variance)
end

Also aliased as: std_dev

std_dev()

Alias for: standard_deviation

sum() click to toggle source

# File lib/enumerable/standard_deviation/standard_deviation.rb, line 2
def sum
  inject(0){|sum, i| sum + i }
end