assert_evenly_distributed.rb

# is this not already provided somewhere?
# even_distribution?([50,49,53]) => true
# even_distribution?(50,33,70]) => false
def even_distribution?(array, slack = 0.1)
  exact_distribution = 1 / array.size.to_f
  slack_val = exact_distribution * slack
  ceil = exact_distribution + slack_val
  floor = exact_distribution - slack_val
  total = array.reduce{ |v,t| v + t }.to_f
  array.each do |element|
    distribution = element / total
    return false unless (floor..ceil).include?(distribution)
  end
  true
end