count_zeros = sum( map(x->(x==0.0), actuals) )
# can be rewritten
count_zeros = sum(x==0.0 for x in actuals)
This shouldn't allocate, because it's using a generator.
I agree with DNF that _v1 is already straight-forward, as far as
performance-sensitive code goes.
On Tuesday, October 25, 2016 at 6:34:45 AM UTC-4, DNF wrote:
>
> Could you explain why you are unhappy with v1? It seems like a
> near-optimal implementation to me. It is idiomatic Julia, clean, clear, and
> fast. Are you certain that you're not looking for a one-liner out of force
> of habit?
>
> On Tuesday, October 25, 2016 at 9:15:54 AM UTC+2, 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
>>
>>
