Append matrices to a numpy array

Question

testMat1 = np.array([[1,2,3,4],[4,5,6,7]])
testMat2 = np.array([[7,8,9,10],[10,11,12,13]])
testMat3 = np.array([[2,4,6,8],[3,5,7,9]])

Here are three matrices of shape (2, 4)

How do I combine them into a multidimensional array with shape (3, 2, 4) ?

np.array([testMat1, testMat2, testMat3]) works properly, however this is not what I am looking for because I will be continuously adding more matrices to the array. I need a way to append new matrices to the array. I tried using np.append but it doesn't seem to be meant for this purpose.

Answer 1

You can use np.vstack() to vertically stack the arrays.

In your case the command would look like this: combined = np.vstack(([testMat1], [testMat2], [testMat3])) which will give you the shape (3, 2, 4)

You can continuously add more arrays and update it by using: combined = np.vstack((combined, [testMat4])) which will give you the shape (4, 2, 4)