numpy arrays

[Manolo Martínez]

On 03/23/16 at 03:06am, Heli wrote:

> I have a 2D numpy array like this:
> 
> [[1,2,3,4],
>  [1,2,3,4], 
>  [1,2,3,4]
>  [1,2,3,4]]
> 
> Is there any fast way to convert this array to 
> 
> [[1,1,1,1],
>  [2,2,2,2]
>  [3,3,3,3]
>  [4,4,4,4]]

You don't mean just transposing your original array, as in
original_array.T, right?

> In general I would need to retrieve every nth element of the interior
> arrays in to single arrays. I know I can loop over and do this, but I
> have really big arrays and I need the fastest way to do this. 

I didn't really get this, so transposing is probably not what you need.
Anyway, just in case!

Manolo