Numpy數據庫中random.rand、random.randn、random.randint區別

random.rand是隨機生成範圍爲（0,1）的數據，如下：

import numpy as np
import pandas as pd
import random
>>> s=pd.DataFrame(np.random.rand(5,4))
>>> s
          0         1         2         3
0  0.344855  0.516473  0.853975  0.564404
1  0.661606  0.436078  0.303183  0.587708
2  0.777793  0.165298  0.692870  0.448780
3  0.968614  0.197588  0.813489  0.906796
4  0.363128  0.069430  0.021099  0.883420

random.randn是生成服從標準正太分佈的數據，如下：

>>> s=pd.DataFrame(np.random.randn(5,4))
>>> s
          0         1         2         3
0 -0.984862 -1.721127 -0.678430  0.298101
1 -0.712040 -0.399124  0.069610 -0.182591
2  0.203461  1.703491  0.186007  1.054380
3 -0.662301 -0.517859  0.346317 -0.176508
4  0.342412  1.180823  0.102282  1.677619
>>> 

random.randint則是生成指定範圍與個數內的整數，如下：

>>> s=pd.Series(np.random.randint(0,7,size=10))
>>> s
0    1
1    4
2    1
3    5
4    4
5    6
6    5
7    4
8    4
9    1
dtype: int32