数组运算

ar = np.arange(6).reshape(2,3)
print('---mean---------------')
print(ar)
print(ar.mean())
print(np.mean(ar,axis=0)) # axis=0 按列
print(np.mean(ar,axis=1)) # axis=1 按行
print('----min------------')

print(ar.min())
print(np.min(ar,axis=0))
print(np.min(ar,axis=1))

print('---max--------------')
print(ar.max())
print('----std--------------')
print(ar.std())
print('----var--------------')
print(ar.var())
print('----sum--------------')
print(ar.sum())
print('----sort--------------')
print(np.sort(np.array([1,4,5,2,7,3])))

结果如下：

---mean---------------
[[0 1 2]
 [3 4 5]]
2.5
[1.5 2.5 3.5]
[1. 4.]
----min------------
0
[0 1 2]
[0 3]
---max--------------
5
----std--------------
1.707825127659933
----var--------------
2.9166666666666665
----sum--------------
15
----sort--------------
[1 2 3 4 5 7]