我有一系列哈希,信息如下。我正试图获得最大,最小和平均的时间睡眠"。我已经尝试过这些问题的答案,但它似乎没有用。
Find the largest value for an array of hashes with common keys?
Finding the element of a Ruby array with the maximum value for a particular attribute
rails select maximum value from array of hash
这是哈希数组
{"id"=>"1", "userId"=>"1", "day"=>"2015-12-05", "startTime"=>"2015-12-05T07:49:30.000Z", "endTime"=>"2015-12-05T15:56:30.000Z", "tzOffset"=>"-08:00", "source"=>"misfit", "mainSleep"=>true, "timeAsleep"=>478, "timeAwake"=>9, "efficiency"=>0, "timeToFallAsleep"=>0, "timeAfterWakeup"=>0, "numberOfWakeups"=>1, "timeInBed"=>0, "createdAt"=>"2015-12-05T21:59:24.935Z", "updatedAt"=>"2015-12-05T21:59:24.935Z", "humanId"=>"1"}
{"id"=>"2", "userId"=>"2", "day"=>"2015-12-04", "startTime"=>"2015-12-04T07:02:30.000Z", "endTime"=>"2015-12-04T14:59:30.000Z", "tzOffset"=>"-08:00", "source"=>"misfit", "mainSleep"=>true, "timeAsleep"=>471, "timeAwake"=>6, "efficiency"=>0, "timeToFallAsleep"=>0, "timeAfterWakeup"=>0, "numberOfWakeups"=>1, "timeInBed"=>0, "createdAt"=>"2015-12-04T16:41:44.198Z", "updatedAt"=>"2015-12-04T16:41:44.198Z", "humanId"=>"2"}
{"id"=>"3", "userId"=>"3", "day"=>"2015-12-03", "startTime"=>"2015-12-03T06:02:32.000Z", "endTime"=>"2015-12-03T13:38:32.000Z", "tzOffset"=>"-08:00", "source"=>"misfit", "mainSleep"=>true, "timeAsleep"=>434, "timeAwake"=>22, "efficiency"=>0, "timeToFallAsleep"=>0, "timeAfterWakeup"=>0, "numberOfWakeups"=>2, "timeInBed"=>0, "createdAt"=>"2015-12-03T15:35:42.903Z", "updatedAt"=>"2015-12-03T15:35:42.903Z", "humanId"=>"3"}
{"id"=>"4", "userId"=>"4", "day"=>"2015-12-02", "startTime"=>"2015-12-02T09:17:33.000Z", "endTime"=>"2015-12-02T15:27:33.000Z", "tzOffset"=>"-08:00", "source"=>"misfit", "mainSleep"=>true, "timeAsleep"=>370, "timeAwake"=>0, "efficiency"=>0, "timeToFallAsleep"=>0, "timeAfterWakeup"=>0, "numberOfWakeups"=>0, "timeInBed"=>0, "createdAt"=>"2015-12-03T04:00:02.050Z", "updatedAt"=>"2015-12-03T04:00:02.050Z", "humanId"=>"4"}
{"id"=>"5", "userId"=>"5", "day"=>"2015-12-01", "startTime"=>"2015-12-01T05:45:36.000Z", "endTime"=>"2015-12-01T13:50:36.000Z", "tzOffset"=>"-08:00", "source"=>"misfit", "mainSleep"=>true, "timeAsleep"=>485, "timeAwake"=>0, "efficiency"=>0, "timeToFallAsleep"=>0, "timeAfterWakeup"=>0, "numberOfWakeups"=>0, "timeInBed"=>0, "createdAt"=>"2015-12-01T17:50:20.168Z", "updatedAt"=>"2015-12-01T17:50:20.168Z", "humanId"=>"5"}
{"id"=>"6", "userId"=>"6", "day"=>"2015-11-30", "startTime"=>"2015-11-30T05:57:38.000Z", "endTime"=>"2015-11-30T14:23:38.000Z", "tzOffset"=>"-08:00", "source"=>"misfit", "mainSleep"=>true, "timeAsleep"=>499, "timeAwake"=>7, "efficiency"=>0, "timeToFallAsleep"=>0, "timeAfterWakeup"=>0, "numberOfWakeups"=>1, "timeInBed"=>0, "createdAt"=>"2015-11-30T16:18:38.276Z", "updatedAt"=>"2015-11-30T16:18:38.276Z", "humanId"=>"6"}
答案 0 :(得分:3)
以下是如何做到这一点:
array.max_by {|x| x['timeAsleep']} # max
array.min_by {|x| x['timeAsleep']} # min
array.map {|x| x['timeAsleep']}.reduce(:+) / array.size.to_f # average
您可以在文档
上阅读有关map
和reduce
的信息
答案 1 :(得分:0)
arr = [
{"id"=>"1", "timeAsleep"=>478, "timeAwake"=>9},
{"id"=>"2", "timeAsleep"=>471, "timeAwake"=>6},
{"id"=>"3", "timeAsleep"=>434, "timeAwake"=>22},
{"id"=>"4", "timeAsleep"=>370, "timeAwake"=>0},
{"id"=>"5", "timeAsleep"=>485, "timeAwake"=>502},
{"id"=>"6", "timeAsleep"=>499, "timeAwake"=>7}]
sleep_times = arr.map { |h| h["timeAsleep"] }
#=> [478, 471, 434, 370, 485, 499]
timeAsleep
sleep_times.minmax
#=> [370, 499]
timeAsleep
sleep_times.reduce(:+).fdiv(arr.size).round(1)
#=> 456.2
最大值所有具有数值的键
(我不确定你是否想要这个。)
arr.map { |h| h.values.select { |v| v.kind_of?(Numeric) }.max }.max
#=> 502
答案 2 :(得分:0)
更有效的方法是对哈希数组进行一次排序,而不是查找最大/最小等。
array = array_hash.sort_by {|k| k["timeAsleep"] }
然后,您可以从已排序的数组
中检索相应的哈希值puts "Hash with Smallest timeAsleep", array[0]
puts "Hash with Largest timeAsleep", array[array.length-1]
if ((array.length % 2) == 0)
puts "Hash with Average timeAsleep", array[(array.size/2)-1]
else
puts "Hash with Average timeAsleep", array[(array.size/2)]
end