On Friday, September 12, 2014 12:41:49 AM UTC-5, Christoph Ortner wrote:
>
> That did work - thank you, see code below. To explain: this came from a
> bottleneck in a bigger code, so my problem there must be a different one.
> -- Christoph
>
> function testtime()
> a1 = rand(10, 10, 100, 100)
> b1 = rand(10, 100, 100)
> c1 = rand(10, 100, 100)
> d1 = []
> const a2 = rand(10,10,100,100)
> const b2 = rand(10,100,100)
> const c2 = rand(10,100,100)
> d2 = []
> @time(begin
> for n = 1:10
> d1 = [ a1[a,b,i,j] .* b1[a,i,j] .* c1[b,i,j] for a = 1:10, b =
> 1:10, i=1:100,j=1:100 ]
> end
> end)
> println(typeof(d1))
> @time(begin
> for n = 1:10
> d2 = [ a2[a,b,i,j] .* b2[a,i,j] .* c2[b,i,j] for a = 1:10, b =
> 1:10, i=1:100,j=1:100 ]
> end
> end)
> println(typeof(d2))
> end
>
A small point about the code. The initialization
d1 = []
is unnecessary. In fact, this assignment initializes d1 to a 1-dimensional
array with 0 elements.
The comprehension creates the array of the correct dimension and populates
it so that initial 1-dimensional array is discarded.
>
> testtime()
>
>
>
>
