numpy数组合并

• 沿着新轴上合并：stack(arrays, axis=0)

沿着轴0合并

In [3]: import numpy as np   ...: a = np.array([[1,2,3],[4,5,6]])   ...: b = np.array([[6,5,6],[7,8,9]])   ...: np.stack((a,b),axis=0)   ...:Out[3]:array([[[1, 2, 3],        [4, 5, 6]],       [[6, 5, 6],        [7, 8, 9]]])In [4]: np.stack((a,b),axis=0).shapeOut[4]: (2, 2, 3)

沿着轴1合并

In [5]: np.stack((a,b),axis=1)Out[5]:array([[[1, 2, 3],        [6, 5, 6]],       [[4, 5, 6],        [7, 8, 9]]])In [6]: np.stack((a,b),axis=1).shapeOut[6]: (2, 2, 3)

沿着轴2合并

In [7]: np.stack((a,b),axis=2)Out[7]:array([[[1, 6],        [2, 5],        [3, 6]],       [[4, 7],        [5, 8],        [6, 9]]])In [8]: np.stack((a,b),axis=2).shapeOut[8]: (2, 3, 2)

• 水平合并：vstack(tup)和row_stack(tup)

In [9]: np.vstack((a,b))Out[9]:array([[1, 2, 3],       [4, 5, 6],       [6, 5, 6],       [7, 8, 9]])In [10]: np.row_stack((a,b))Out[10]:array([[1, 2, 3],       [4, 5, 6],       [6, 5, 6],       [7, 8, 9]])

• 垂直合并：hstack(tup)和column_stack(tup)

In [11]: np.hstack((a,b))Out[11]:array([[1, 2, 3, 6, 5, 6],       [4, 5, 6, 7, 8, 9]])In [12]: np.column_stack((a,b))Out[12]:array([[1, 2, 3, 6, 5, 6],       [4, 5, 6, 7, 8, 9]])