Tue Oct 19 17:02:20 2021 VSTACK_TEST Python version: 3.6.9 np.vstack() vertically stacks arrays of same column dimension. Matrix A: Col: 0 1 2 Row 0: 11 12 13 1: 21 22 23 2: 31 32 33 3: 41 42 43 Matrix B: Col: 0 1 2 Row 0: 501 502 503 1: 601 602 603 Matrix vstack(A,B) Col: 0 1 2 Row 0: 11 12 13 1: 21 22 23 2: 31 32 33 3: 41 42 43 4: 501 502 503 5: 601 602 603 Matrix vstack(A[0:2,:],B,A{2:4,:]) Col: 0 1 2 Row 0: 11 12 13 1: 21 22 23 2: 501 502 503 3: 601 602 603 4: 31 32 33 5: 41 42 43 VSTACK_TEST: Normal end of execution. Tue Oct 19 17:02:21 2021