3d Numpy array to 2d

Question

I have a 3d matrix like this

arange(16).reshape((4,2,2)) array([[[ 0,  1],         [ 2,  3]],          [[ 4,  5],         [ 6,  7]],          [[ 8,  9],         [10, 11]],          [[12, 13],         [14, 15]]]) 

and would like to stack them in grid format, ending up with

array([[ 0,  1,  4,  5],        [ 2,  3,  6,  7],        [ 8,  9, 12, 13],        [10, 11, 14, 15]]) 

Is there a way of doing without explicitly hstacking (and/or vstacking) them or adding an extra dimension and reshaping (not sure this would work)?

Thanks,

Answer 1

In [27]: x = np.arange(16).reshape((4,2,2))  In [28]: x.reshape(2,2,2,2).swapaxes(1,2).reshape(4,-1) Out[28]:  array([[ 0,  1,  4,  5],        [ 2,  3,  6,  7],        [ 8,  9, 12, 13],        [10, 11, 14, 15]]) 

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I've posted more general functions for reshaping/unshaping arrays into blocks, here.