Question

I have an numpy int32 array called a that has shape (4, 8, 3). I want to reshape this array to one that is of size (4, 12, 3). How do I do that?

I have tried using reshape, but reshape requires that the array be the same size.

Answer 1

I might be wrong but : a numpy array isn’t supposed to be mutated this way.
When you do a reshape what you’re actually doing is just changing the order/way in which the bytes/elements are read

What you want to do is create a new array that is bigger and contains the data of the previous array plus other stuff. You have to tell Numpy WHERE you want the new stuff and where you want the old stuff.

i.e:

new_array = np.zeros((4, 12, 3))
new_array[:, :8, :] = old_array

This example adds 4 additionnal “columns” on your array at the end of the second dimension.