python - Concatenate two numpy arrays in the 4th dimension

Question

I have two numpy arrays with three dimensions (3 x 4 x 5) and I want to concatenate them so the result has four dimensions (3 x 4 x 5 x 2). In Matlab, this can be done with cat(4, a, b), but not in Numpy.

For example:

a = ones((3,4,5))
b = ones((3,4,5))
c = concatenate((a,b), axis=3) # error!

To clarify, I wish c[:,:,:,0] and c[:,:,:,1] to correspond to the original two arrays.

Answer 1

Here you go:

import numpy as np
a = np.ones((3,4,5))
b = np.ones((3,4,5))
c = np.concatenate((a[...,np.newaxis],b[...,np.newaxis]),axis=3)