maybe with reduce ?

```
function mapeBase_v4(A::Vector{Float64}, F::Vector{Float64})
  function abscount(prev, current)
    current[2] == 0.0 && return prev
    index, item = current
    (prev[1] + abs( 1 - F[index] / item), prev[2] + 1)
  end
  reduce(abscount, (0.0, 0), enumerate(A))
end
```

2016-10-25 9:43 GMT+02:00 Jeffrey Sarnoff <jeffrey.sarn...@gmail.com>:

> This may do what you want.
>
> function mapeBase_v3(actuals::Vector{Float64}, forecasts::Vector{Float64})
> # actuals - actual target values
> # forecasts - forecasts (model estimations)
>
>   sum_reldiffs = sumabs((x - y) / x for (x, y) in zip(actuals, forecasts) if 
> x != 0.0)  # Generator
>
>   count_zeros = sum( map(x->(x==0.0), actuals) )
>   count_nonzeros = length(actuals) - count_zeros
>   sum_reldiffs, count_nonzeros
> end
>
>
>
>
> On Tuesday, October 25, 2016 at 3:15:54 AM UTC-4, Martin Florek wrote:
>>
>> Hi all,
>> I'm new in Julia and I'm doing refactoring. I have the following function:
>>
>> function mapeBase_v1(A::Vector{Float64}, F::Vector{Float64})
>>   s = 0.0
>>   count = 0
>>   for i in 1:length(A)
>>     if(A[i] != 0.0)
>>       s += abs( (A[i] - F[i]) / A[i])
>>       count += 1
>>     end
>>   end
>>
>>   s, count
>>
>> end
>>
>> I'm looking for a simpler variant which is as follows:
>>
>> function mapeBase_v2(A::Vector{Float64}, F::Vector{Float64})
>> # A - actual target values
>> # F - forecasts (model estimations)
>>
>>   s = sumabs((x - y) / x for (x, y) in zip(A, F) if x != 0) # Generator
>>
>>   count = length(A) # ???
>>   s, countend
>>
>>
>> However with this variant can not determine the number of non-zero elements. 
>> I found option with length(A[A .!= 0.0]), but it has a large allocation. 
>> Please, someone knows a solution with generator, or variant v1 is very good 
>> choice?
>>
>>
>> Thanks in advance,
>> Martin
>>
>>

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