rails，group for average，然后再次组合sum(rails, group for average and then group again for sum)

rails，group for average，然后再次组合sum(rails, group for average and then group again for sum)

示例：一个表，每隔几分钟就会节省一次功耗。

我正在尝试使用groupdate gem来处理这些数据：

@kWh = Consumption.group_by_hour(:at).average(:kw) @kWh_per_day = @kWh.group_by_day(:at).sum(:average_kw)

对于第二行，我收到一个错误：“没有给出块”

任何正确方向的推动都将受到赞赏。

Example: a table, in which the power consumption is saved every few minutes.

What i am trying to do with this data using the groupdate gem:

@kWh = Consumption.group_by_hour(:at).average(:kw) @kWh_per_day = @kWh.group_by_day(:at).sum(:average_kw)

For the second line I get an error: "no block given"

Any push in the right direction would be appreciated.

最满意答案

......最终有效的是什么，虽然它看起来不是很强烈：

@kWh = Consumption.group_by_hour(:at).average(:kw) @kWh_per_day = Hash [@kWh.group_by_day { |h| h[0] }.map { |k,v| [k, v.map { |j| j[1] }.reduce(:+)] } ]

... what finally worked, though it doesn't look very elegeant:

@kWh = Consumption.group_by_hour(:at).average(:kw) @kWh_per_day = Hash [@kWh.group_by_day { |h| h[0] }.map { |k,v| [k, v.map { |j| j[1] }.reduce(:+)] } ]