Method: Array#probability

Defined in:
lib/core/facets/array/probability.rb

#probability ⇒ Object

Generates a hash mapping each unique element in the array to the relative frequency, i.e. the probablity, of it appearence.

[:a, :b, :c, :c].probability  #=> {:a=> 0.25, :b=>0.25, :c=>0.5}

CREDIT: Brian Schröder



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# File 'lib/core/facets/array/probability.rb', line 10

def probability
  probs = Hash.new(0.0)
  size = 0.0
  each do |e|
    probs[e] += 1.0
    size += 1.0
  end
  probs.keys.each{ |e| probs[e] /= size }
  probs
end