On Monday, December 15, 2014 5:36:54 PM UTC-5, yu...@altern.org wrote:
>
> Both Nx1 and 1xN arrays are matrices (ndims=2), but N-vectors
> (ndims=1) are almost functionally equivalent to Nx1 matrices, i.e. you can
> use them in matrix multiplication and such.
>
Ah. Interesting:
~~~
julia> [1 2 3] # "row vector"
1x3 Array{Int64,2}:
1 2 3
julia> [1, 2, 3] # "column vector", aka "vector" (a Vector)
3-element Array{Int64,1}:
1
2
3
julia> ndims([1 2 3; 4 5 6])
2
julia> ndims([1 2 3])
2
julia> ndims([1, 2, 3])
1
julia> size([1 2 3])
(1,3)
julia> size([1, 2, 3])
(3,)
~~~
> This is a bit weird at first but it doesn't cause much problems in
> practice, even though it can be a bit funny sometimes:
>
> julia> x == x''
> false
>
>
Ok:
~~~
julia> [1, 2, 3] # ndims == 1
3-element Array{Int64,1}:
1
2
3
julia> [1 2 3]' # but here, ndims == 2
3x1 Array{Int64,2}:
1
2
3
~~~
Thanks!
