Excuse me，



 ptrblck:

If so, then I think the difference between both approaches could come from a different order of the reductions and thus accumulated small absolute errors due to the limited floating point precision


Can I have the method to overcome such problem?
Cause in my situation, the reduction of mean return a good result, however, the reduction of none return a totally bad result.
If I wanna use the reduction of none to cooperate the sample weight, I must overcome the problem above.
Appreciate for your help.