[Numpy-discussion] How to combine a pair of 1D arrays?

Zachary Pincus zachary.pincus@yale....
Wed Apr 14 12:20:08 CDT 2010


> On Wed, Apr 14, 2010 at 10:25, Peter Shinners <pete@shinners.org>  
> wrote:
>> Is there a way to combine two 1D arrays with the same size into a 2D
>> array? It seems like the internal pointers and strides could be
>> combined. My primary goal is to not make any copies of the data.
>
> There is absolutely no way to get around that, I am afraid.

You could start with the 2d array... instead of:
>  >>> a = np.array((1,2,3,4))
>  >>> b = np.array((11,12,13,14))
>  >>> c = np.magical_fuse(a, b)   # what goes here?

perhaps something like:

  >>> c = np.empty((2,4), int)
  >>> a = c[0]
  >>> b = c[1]

Now a and b are views on c. So if you (say) pass them to, say, some  
(strides-aware) C routine that fills them in element-by-element, c  
will get filled in at the same time.

Zach




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