Module: TrickBag::Numeric::Totals

Defined in:
lib/trick_bag/numeric/totals.rb

Class Method Summary collapse

Class Method Details

.fraction_of_total_hash(the_hash) ⇒ Object

Given a hash whose values are numbers, produces a new hash with the same keys as the original hash, but whose values are the % of total.

Ex: fraction_of_total_hash({ foo: 10.0, bar: 20.0, baz: 30.0, razz: 40.0 })

=> {:foo=>0.1, :bar=>0.2, :baz=>0.3, :razz=>0.4}



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# File 'lib/trick_bag/numeric/totals.rb', line 32

def fraction_of_total_hash(the_hash)
  new_hash = percent_of_total_hash(the_hash)
  new_hash.keys.each do |key|
    new_hash[key] = new_hash[key] / 100.0
  end
  new_hash
end

.map_fraction_of_total(inputs) ⇒ Object

e.g.: map_fraction_of_total [10,20,30] => [0.16666666666666666, 0.3333333333333333, 0.5]

Returns:

  • a collection containing the corresponding fractions of total of those numbers



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# File 'lib/trick_bag/numeric/totals.rb', line 11

def map_fraction_of_total(inputs)
  return [] if inputs.size == 0
  sum = Float(inputs.inject(:+))
  inputs.map { |n| n / sum }
end

.map_percent_of_total(inputs) ⇒ Object

e.g. map_percent_of_total [10,20,30] => [16.666666666666664, 33.33333333333333, 50.0]

Returns:

  • a collection containing the corresponding percents of total of those numbers



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# File 'lib/trick_bag/numeric/totals.rb', line 22

def map_percent_of_total(inputs)
  map_fraction_of_total(inputs).map { |n| n * 100 }
end

.percent_of_total_hash(the_hash) ⇒ Object

Given a hash whose values are numbers, produces a new hash with the same keys as the original hash, but whose values are the % of total.

Ex: percent_of_total_hash({ foo: 10.0, bar: 20.0, baz: 30.0, razz: 40.0 })

=> {:foo=>10.0, :bar=>20.0, :baz=>30.0, :razz=>40.0}



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# File 'lib/trick_bag/numeric/totals.rb', line 46

def percent_of_total_hash(the_hash)
  sum = Float(the_hash.values.inject(:+))
  keys = the_hash.keys
  keys.each_with_object({}) do |key, percent_total_hash|
    percent_total_hash[key] = 100 * the_hash[key] / sum
  end
end