Question

I’m still getting the hang of working with numpy and array-wise operations.

I’m looking for the way of getting the row-wise average of a list of 2D arrays.

E.g I have a 4x3x25 array and I’m looking to get a 3×25 array of the row-wise averages.

Answer 1

If everything’s in one 3D array already, you can just do:

A.mean(axis=0)

…which will operate along the first dimension.

If it’s actually just a list of 2D arrays, you’ll have to convert it to a 3D array first. I would do:

A = np.dstack(list_of_arrays)  # Combine the 2D arrays along a new 3rd dimension
A.mean(axis=2)                 # Calculate the means along that new dimension