- import numpy as np
- data = np.random.rand(10,2)
-
- print(data)
初始数据
[[0.85482143 0.87208392]
[0.15226363 0.52549581]
[0.85199583 0.63840434]
[0.37461595 0.7699527 ]
[0.62885774 0.50949107]
[0.13442721 0.33380331]
[0.72998008 0.01574827]
[0.20302876 0.19834324]
[0.78084008 0.34859342]
[0.1350378 0.55653729]]
python行索引【0,1,2,3】行
print(data[[0,1,2,3]])
[[0.85733026 0.51441212]
[0.9297203 0.32537354]
[0.55053671 0.98026599]
[0.01811309 0.78720568]]
python列索引【0】列
print(data[:,0])
[0.85733026 0.9297203 0.55053671 0.01811309 0.72665786 0.51680252
0.89344144 0.80729948 0.05969606 0.71608088]
- import numpy as np
- import matplotlib.pyplot as plt
- data = np.random.rand(10000,2) #随机生成10000行两列个数据
-
- x = data[:,0]
- y = data[:,1]
- idx = x**2+y**2 < 1 #索引条件圆形中x和y都大于0的数据
- plt.plot(x[idx],y[idx],'go',markersize=1)
- plt.show()
效果

- import numpy as np
- import matplotlib.pyplot as plt
- data = 2*np.random.rand(10000,2) - 1 #定义域转为[-1,1]
-
- x = data[:,0]
- y = data[:,1]
- idx = x**2+y**2 < 1 #圆形
- plt.plot(x[idx],y[idx],'go',markersize=1)
- plt.show()
效果

- import numpy as np
- import matplotlib.pyplot as plt
- data = 2*np.random.rand(10000,2) - 1
-
- x = data[:,0]
- y = data[:,1]
- idx = x**2+y**2 < 1
- hole = x**2 + y**2 < 0.25
- idx = np.logical_and(idx,~hole) #numpy中的逻辑与,大圆和不包含小圆区域取相同的部分
- plt.plot(x[idx],y[idx],'go',markersize=1)
- plt.show()
效果

import numpy as np import matplotlib.pyplot as plt p = np.random.rand(10000) np.set_printoptions(edgeitems=5000, suppress=True) plt.hist(p,bins=20,color='g') #分成20份 plt.show()效果
import numpy as np import matplotlib.pyplot as plt p = np.random.rand(10000) np.set_printoptions(edgeitems=5000, suppress=True) plt.hist(p,bins=20, color='g', edgecolor='k') plt.show()效果
- import numpy as np
- import matplotlib.pyplot as plt
-
- N = 10000
- times = 100
- z = np.zeros(N)
- for i in range(times):
- z += np.random.rand(N)
- z /= times
- plt.hist(z, bins = 20, color = 'm', edgecolor='k')
- plt.show()
效果

- import numpy as np
- import pandas as pd
-
- d = np.random.rand(3,4)
- print(d)
- print(type(d))
- data = pd.DataFrame(data=d,columns = list('abcd'))
- print('='*50)
- print(data)
- print(type(data))
- print(data['b'])
- data.to_csv('./data.dsv', index=False, header=True)
- print('文件保存成功')
效果

- import numpy as np
- import matplotlib.pyplot as plt
-
- # [-4,2]
- d = np.random.rand(100)*6-4
- print(d)
- plt.plot(d,'r.')
- plt.show()
效果

- import numpy as np
-
- if __name__=='__main__':
- a = np.arange(1,10000)
- print(a)
- print(np.sqrt(6*np.sum(1/(a**2))))
-
效果
[ 1 2 3 ... 9997 9998 9999]
3.141497154397623
- import numpy as np
-
- if __name__=='__main__':
- x = np.arange(1,20)
- print(np.sum(1/x.cumprod()) + 1) #cumprod求阶乘
效果
2.7182818351251554
import numpy as np import matplotlib.pyplot as plt x = np.linspace(0,1,100) print(x) y = x**x plt.plot(x,y,'r-',linewidth=2) plt.show()效果
import numpy as np import matplotlib.pyplot as plt x = np.linspace(0,1,100) print(x) y = x**x plt.plot(x,y,'r--',linewidth=2) plt.show()效果
import numpy as np import matplotlib.pyplot as plt x = np.linspace(0,1,100) print(x) y = x**x plt.plot(x,y,'r:',linewidth=2) plt.show()效果
import numpy as np import matplotlib.pyplot as plt x = np.linspace(0,1,100) print(x) y = x**x plt.plot(x,y,'r.',linewidth=2) plt.show()
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