Sha256: 9259f03a69948003c45b7cc6c926f387d50a29635728f55dd1815d58947557d8
Contents?: true
Size: 786 Bytes
Versions: 8
Compression:
Stored size: 786 Bytes
Contents
class Array
# 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
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
#--
# Old Definition ...
#
# def probability
# arr = self.to_a
# probHash = Hash.new
# size = arr.size.to_f
# arr.uniq.each do |i|
# ct = arr.inject(0) do |mem,obj|
# obj.eql?(i) ? (mem+1) : mem
# end
# probHash[i] = ct.to_f/size
# end
# probHash
# end
#++
end
Version data entries
8 entries across 7 versions & 1 rubygems