If you look at the bytes allocated, it seems that Andrea did that.

What version of Julia are you running, Andrea?

Kevin


On Fri, Jan 17, 2014 at 11:31 AM, Eric Davies <[email protected]> wrote:

> Running once before will cause compilation of the called functions for the
> given types.
>
> julia> A = randn(1000,1000); A = A+A'+eye(1000); x = randn(1000);
>
> julia> @time A\x;
> @time A\x;
> elapsed time: 0.752317463 seconds (48614156 bytes allocated)
>
> julia> @time A\x;
> @time A\x;
> elapsed time: 0.031127576 seconds (8016424 bytes allocated)
>
> Any subsequent calls to A\x with different random initializations will
> have performance like the second call shown here.
>
>
> On Friday, 17 January 2014 13:21:21 UTC-6, Andrea Vigliotti wrote:
>>
>> Hi All,
>>
>> I was comparing the performance of Julia and Matlab in solving systems of
>> linear equations and I got the following
>>
>> Matlab:
>> >> A = randn(1000); A = A+A'+eye(1000); x = randn(1000,1);
>> >> tic; A\x; toc
>> Elapsed time is 0.034763 seconds.
>>
>> Julia:
>> julia> A = randn(1000,1000); A = A+A'+eye(1000); x = randn(1000);
>>
>> julia> @time A\x;
>> elapsed time: 0.192572124 seconds (8012424 bytes allocated)
>>
>> I was wondering whether there is anything I can do to improve the
>> performances of Julia in solving this kind of problems?
>>
>> many thanks!
>> andrea
>>
>

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