比较浮点数组时 rspec 测试的舍入问题

我想检查一种方法的结果：

 result.should  == [1.0,2.0,3.0]

但我收到一个错误：

   expected: [1.0, 2.0, 3.0]
        got: [1.0, 2.0, 3.0] (using ==)

我认为问题在于四舍五入，但我不知道如何比较它们，例如偏差为0.1。

谢谢你，呼吸。 我写了自己的匹配器，如果它对某人有帮助：

RSpec::Matchers.define :be_closed_array do |expected, truth|
  match do |actual|
    same = 0
    for i in 0..actual.length-1
      same +=1 if actual[i].round(truth) == expected[i].round(truth)
    end
    same == actual.length
  end

  failure_message_for_should do |actual|
    "expected that #{actual} would be close to #{expected}"
  end

  failure_message_for_should_not do |actual|
    "expected that #{actual} would not be close to #{expected}"
  end

  description do
    "be a close to #{expected}"
  end
end

使用（已弃用）2.7.0 https://github.com/rspec/rspec-expectations/commit/4638609046a120c86d48a0253b471db55a5fd441#diff-a26c79378299c0868d0462d2000c54e204e9b854f1dd772c05e7deb588033ff0R3，删除于3.0.0 https://github.com/rspec/rspec-expectations/commit/a00be5b15dacfae7aa0be68fdd4ccd1ebd2ddf1a#diff-4ac680eeaffa2461320261649ec69d2b543331a37dc7ac88c33de1f77163293c):

 .should be_close

Or even:

 .should be_within

参考这里http://rubydoc.info/gems/rspec-expectations/2.4.0/RSpec/Matchers http://rubydoc.info/gems/rspec-expectations/2.4.0/RSpec/Matchers