# 导包

import numpy as np

np.random.seed(10)

L = np.random.random(100)

sum(L)

np.sum(L) 

np.min(L) 

np.max(L)

X = np.arange(16).reshape(4,-1)

"""

array([[ 0,  1,  2,  3],

       [ 4,  5,  6,  7],

       [ 8,  9, 10, 11],

       [12, 13, 14, 15]])

"""

# np.sum(X)   # 120

# np.sum(X, axis=0)  # array([24, 28, 32, 36])

# np.sum(X, axis=1)  # array([ 6, 22, 38, 54])

np.prod(X)  #

np.prod(X + 1)  #

np.mean(X)   # 7.5

np.median(X)  # 7.5

np.random.seed(100)

big_array = np.random.random(1000000)

# #取百分位分位点上的数，50%分位数

np.percentile(big_array, q=50)   # 0.4998651570582321

for percent in [0, 25, 50, 75, 100]:

    print(np.percentile(big_array, q=percent))

"""

1.3820074052928177e-06

0.24934216925258532

0.4998651570582321

0.7497718195194847

0.9999960107137339

"""

np.var(big_array)

np.std(big_array) 

x = np.random.normal(0, 1, 1000000)

np.mean(x)

np.std(x)