What is the difference between (4,) and (4.1) for a form in Numpy?

Question

I have two ndarray A and B , one has the form (4,) and another one (4,1) .

When I want to calculate the cosine distance using this , it throws some exceptions that complain about two objects are not aligned

Does anyone have any ideas about this? Thanks!

Answer 1

One is a one-dimensional array, the other is a two-dimensional array.

Example:

 >>> import numpy as np >>> a = np.arange(4).reshape(4,1) >>> a array([[0], [1], [2], [3]]) >>> a.ravel() array([0, 1, 2, 3]) >>> a.squeeze() array([0, 1, 2, 3]) >>> a[:,0] array([0, 1, 2, 3]) >>> >>> a[:,0].shape (4,)