inject 问题。怪！

arr = [0.054954087385762455, 0.5093998626512432, 5.880466289995431, 0.8639141517665208, 0.2152490168404071]

  sum = arr.inject {|sum, item| sum + item}

  tmp = 0
  arr.each do |pwr|
    tmp = tmp + (pwr / sum - 0.2) ** 2
  end
  puts tmp #   0.42948006253339877

pp ( arr.inject { |result, item| result + (item / sum - 0.2) ** 2} ) # 0.4473023458029664

inject(0)

[code="ruby"]
pp ( arr.inject(0) { |result, item| result + (item / sum - 0.2) ** 2} ) # 0.42948006253339877
[/code]