[Numpy-discussion] Re: What am I missing about concatenate?

Robert Kern robert.kern at gmail.com
Thu Jun 1 11:43:00 CDT 2006


Christopher Barker wrote:
> I want to take two (2,) arrays and put them together into one (2,2)
> array. I thought one of these would work:
> 
>>>> N.concatenate(((1,2),(3,4)),0)
> array([1, 2, 3, 4])
>>>> N.concatenate(((1,2),(3,4)),1)
> array([1, 2, 3, 4])
> 
> Is this the best I can do?
> 
>>>> N.concatenate(((1,2),(3,4))).reshape(2,2)
> array([[1, 2],
>        [3, 4]])
> 
> Is it because the arrays I'm putting together are rank-1?

Yes.

Look at vstack() (and also its friends hstack(), dstack() and column_stack() for
completeness).

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco





More information about the Numpy-discussion mailing list