a weighted random method

gistfile1.rb

#
# a weighted random
#
the_list    = { "five" => 5, "three" => 3, "one" => 1 }
result_hash = { "five" => 0, "three" => 0, "one" => 0 }
count       = 3

def weighted_random(list, count)

  weighted_list = []

  list.each do |key, val|
    val.times do
      weighted_list << key
    end
  end

  result = []

  count.times do
    result << weighted_list[rand(weighted_list.length)]
  end

  result
end

all_results = []
1000.times do
  all_results << weighted_random(the_list, count)
end

all_results.flatten.each { |v| result_hash[v] += 1 }

puts result_hash.inspect

puts "three to one ratio = #{result_hash[:three.to_s] / result_hash[:one.to_s]}"
puts "five to one ratio  = #{result_hash[:five.to_s]  / result_hash[:one.to_s]}"