vstack & hstack & concatenate

Posted 2020-08-13

 1 In[86]: a,b
 2 Out[86]: (array([1, 2, 3]), array([4, 5, 6]))
 3 In[87]: np.concatenate((a,b),axis=0)
 4 Out[87]: array([1, 2, 3, 4, 5, 6])
 5 In[88]: np.concatenate((a,b),axis=1)
 6 Out[88]: array([1, 2, 3, 4, 5, 6])
 7 In[89]: np.vstack((a,b))
 8 Out[89]: 
 9 array([[1, 2, 3],
10        [4, 5, 6]])
11 In[90]: np.hstack((a,b))
12 Out[90]: array([1, 2, 3, 4, 5, 6])
13 In[93]: a1
14 Out[93]: 
15 array([[1, 2, 3],
16        [4, 5, 6]])
17 In[94]: a2
18 Out[94]: 
19 array([[ 7,  8,  9],
20        [10, 11, 12]])
21 In[95]: np.concatenate((a1,a2),axis=0)
22 Out[95]: 
23 array([[ 1,  2,  3],
24        [ 4,  5,  6],
25        [ 7,  8,  9],
26        [10, 11, 12]])
27 In[96]: np.concatenate((a1,a2),axis=1)
28 Out[96]: 
29 array([[ 1,  2,  3,  7,  8,  9],
30        [ 4,  5,  6, 10, 11, 12]])
31 In[97]: np.vstack((a1,a2))
32 Out[97]: 
33 array([[ 1,  2,  3],
34        [ 4,  5,  6],
35        [ 7,  8,  9],
36        [10, 11, 12]])
37 In[98]: np.hstack((a1,a2))
38 Out[98]: 
39 array([[ 1,  2,  3,  7,  8,  9],
40        [ 4,  5,  6, 10, 11, 12]])