[Numpy-discussion] easy way to collapse the last two dimension of an array?

Robert Kern robert.kern@gmail....
Mon Jun 3 04:39:12 CDT 2013


On Mon, Jun 3, 2013 at 9:44 AM, Chao YUE <chaoyuejoy@gmail.com> wrote:
> Dear all,
>
> I have an array with 4 dim:
>
> In [24]: dd.shape
> Out[24]: (12, 13, 120, 170)
>
> I would like to collapse the last two dim for applying np.sum(axis=-1)
>
> In [25]: dd.reshape(12,13,-1).shape
> Out[25]: (12, 13, 20400)
>
> is there a more general way to do this? something like
> In [21]: dd.reshape(*dd.shape[0:2],-1).shape
> ------------------------------------------------------------
>    File "<ipython console>", line 1
> SyntaxError: only named arguments may follow *expression (<ipython console>,
> line 1)

dd.reshape(dd.shape[:-2] + (-1,))

--
Robert Kern


More information about the NumPy-Discussion mailing list