I know, I was asking about that being the default behaviour of *
On Tuesday, October 18, 2016 at 2:10:14 PM UTC-4, Stefan Karpinski wrote:
>
> That's what A_mul_B! does.
>
> On Tue, Oct 18, 2016 at 1:45 PM, Jérémy Béjanin <jeremy....@gmail.com
> <javascript:>> wrote:
>
>> I think this is something I might have read about in the past, but are
>> there plans to make y = a*b use an already allocated y?
>>
>> On Tuesday, October 18, 2016 at 12:38:00 PM UTC-4, Stefan Karpinski wrote:
>>>
>>> A_mul_B!(Y, A, B) -> Y
>>>
>>> Calculates the matrix-matrix or matrix-vector product A⋅B and stores
>>> the result in Y, overwriting the
>>> existing value of Y. Note that Y must not be aliased with either A or
>>> B.
>>>
>>> julia> A=[1.0 2.0; 3.0 4.0]; B=[1.0 1.0; 1.0 1.0]; Y = similar(B);
>>> A_mul_B!(Y, A, B);
>>>
>>> julia> Y
>>> 2×2 Array{Float64,2}:
>>> 3.0 3.0
>>> 7.0 7.0
>>>
>>> On Tue, Oct 18, 2016 at 10:27 AM, <zamani.m...@gmail.com> wrote:
>>>
>>>> hi guys
>>>> is there a way to reduce allocated memory in matrix multiplications?
>>>>
>>>> for example this code blew in my machine gives :
>>>>
>>>> function test4(n)
>>>> a = rand(n,n)
>>>> for i = 1:100
>>>> a*a
>>>> end
>>>> end
>>>>
>>>>
>>>> ---------------------- answer ----------------------
>>>> test4(1)
>>>> # force compiling
>>>>
>>>> @time test4(1000)
>>>> 16.589743 seconds (433 allocations: 770.587 MB, 0.68% gc time)
>>>>
>>>
>>>
>
