Indeed, it seems to be that, although it must be
a = zeros(Int, dims...)::Vector{Int}
rather than
a::Vector{Int} = zeros(Int, dims...)
Even so, test1 still allocates much more memory .
On Sunday, January 5, 2014 12:12:19 AM UTC, Dahua Lin wrote:
>
> I think the reason is that the compiler fails to infer the type of a for
> test1 & test2. I guess if you write a::Vector{Int} = zeros(Int, dims...),
> the situation would be quite different.
>
> - Dahua
>
> On Saturday, January 4, 2014 3:44:19 PM UTC-6, Milan Bouchet-Valat wrote:
>>
>> Hi!
>>
>> I'd like propose you a small game about performance. In the following
>> gist, I provide three very similar short functions; the first one allocates
>> much more memory and is much slower than the two others. Can someone find
>> an explanation? ;-)
>>
>> https://gist.github.com/nalimilan/8261056
>>
>> The real-world scenario is again building a frequency table. I discovered
>> that when doing a = zeros(Int, dims) I really had to make dim a tuple
>> rather than an array, which forces me to use two versions of the same data,
>> one in each type
>>
>> Thanks for the help!
>>
>
