1 ,向量 × 數字 : nd01 * 2
- 代碼 :
if __name__ == '__main__':
nd01 = np.array([1,2,3,4])
nd02 = np.array([2,3,4,5])
res = nd01 * 2
print(nd01)
print(res)
==========================
[1 2 3 4]
[2 4 6 8]
2 ,向量 + 向量 : nd01 + nd02
- 代碼 :
if __name__ == '__main__':
nd01 = np.array([1,2,3,4])
nd02 = np.array([2,3,4,5])
res = nd01 + nd02
print(nd01)
print(nd02)
print(res)
===============================
[1 2 3 4]
[2 3 4 5]
[3 5 7 9]
3 ,向量之間的內積 : nd01.dot(nd02)
- 代碼 :
if __name__ == '__main__':
nd01 = np.array([1,2,3,4])
nd02 = np.array([2,3,4,5])
res = nd01.dot(nd02)
print(nd01)
print(nd02)
print(res)
=================================
[1 2 3 4]
[2 3 4 5]
40
4 ,矩陣拼接 : 橫向 np.hstack((nd01,nd02))
- 代碼 :
if __name__ == '__main__':
nd01 = np.array([[1,2],[3,4]])
nd02 = np.array([[5,6],[7,8]])
nd03 = np.hstack((nd01,nd02))
print(nd01)
print(nd02)
print(nd03)
============================
[[1 2]
[3 4]]
==========
[[5 6]
[7 8]]
===========
[[1 2 5 6]
[3 4 7 8]]
5 ,矩陣拼接 : 縱向 np.vstack((nd01,nd02))
6 ,矩陣切割 : np.hsplit ,np.vsplit
- 橫向切分 : 平均分
if __name__ == '__main__':
nd01 = np.ceil(np.random.random((2,12)) * 10)
nd02 = np.hsplit(nd01,3)
print(nd01)
print(nd02)
==================
[array([[6., 4., 8., 3.],
[1., 9., 9., 2.]]),
array([[ 4., 5., 10., 8.],
[10., 5., 3., 3.]]),
array([[ 2., 8., 10., 9.],
[10., 3., 1., 2.]])]
- 橫向切分 : 指定位置分
if __name__ == '__main__':
nd01 = np.ceil(np.random.random((2,12)) * 10)
nd02 = np.hsplit(nd01,(2,4))
print(nd01)
print(nd02)
==========================
[[ 4. 5. 7. 8. 10. 1. 7. 8. 10. 2. 10. 9.]
[ 4. 1. 9. 4. 10. 10. 4. 5. 3. 3. 7. 10.]]
[array([[4., 5.],
[4., 1.]]),
array([[7., 8.],
[9., 4.]]),
array([[10., 1., 7., 8., 10., 2., 10., 9.],
[10., 10., 4., 5., 3., 3., 7., 10.]])]
7 ,矩陣的轉置 : nd01.T
- 代碼 :
if __name__ == '__main__':
nd01 = np.array([[1,2],[3,4]])
nd02 = nd01.T
print(nd01)
print(nd02)
===========================
[[1 2]
[3 4]]
============
[[1 3]
[2 4]]
8 ,多乘擴展 : np.tile(nd01,(2,3))
- 代碼 :
if __name__ == '__main__':
nd01 = np.array([1,2,3,4])
nd02 = np.tile(nd01,(2,3))
print(nd01)
print(nd02)
===============================
[1 2 3 4]
[[1 2 3 4 1 2 3 4 1 2 3 4]
[1 2 3 4 1 2 3 4 1 2 3 4]]