flatten() 3-dimensional

>>> x = np.array([[[0,0.314], [1,0.5],[2,17]],[[0,2],[1,0.67], [42,4]]], float)

>>> x[1,1,0]

1.0

>>> x[1,1,1]

0.67000000000000004

>>> x[1,2,1]

4.0

>>> x[1,2,0]

42.0

>>> y = x.flatten()

>>> y

array([ 0. , 0.314, 1. , 0.5 , 2. , 17. , 0. , 2. , 1. , 0.67, 42. , 4. ])