If the Array is anything other than normal, it should have a non-standard
type. So the answer for your two examples is no, as you can see by
creating them and looking at the type, which is simply Array{Float64,2}.
There are however some special Array like types, such as I, which acts as
an matrix with diagonal ones, but is implemented in a more efficient manner.
*julia> **ones(2,2)*
*2x2 Array{Float64,2}:*
* 1.0 1.0*
* 1.0 1.0*
*julia> **zeros(2,2)*
*2x2 Array{Float64,2}:*
* 0.0 0.0*
* 0.0 0.0*
*julia> **ones(2,2)+I*
*2x2 Array{Float64,2}:*
* 2.0 1.0*
* 1.0 2.0*
*julia> **I*
*UniformScaling{Int64}*
*1*I*
On Friday, December 12, 2014 3:45:16 PM UTC-7, Petr Krysl wrote:
>
> Are perhaps matrices initialized as all zeros or identity matrices marked
> as special behind the scenes, so that no actual processing is done when
> there used for instance in multiplication?
>
> Thanks,
> Petr
>
