Python中的 numpy.around()

numpy.around(arr, decimals = 0, out = None) ：这个数学函数帮助用户将数组元素均匀地舍入到给定的小数位数。

参数 ：

array : [array_like] Input array.
decimal : [int, optional] Decimal places we want to round off.

Default = 0. In case of -ve decimal, it specifies the n0. of positions to the left of the decimal point.

out : [optional] Output resulted array

返回 ：

An array with all array elements being rounded off,
having same type as input 

代码#1：工作

# Python program explaining
# around() function
  
import numpy as np
  
in_array = [.5, 1.5, 2.5, 3.5, 4.5, 10.1]
print ("Input array : \n", in_array)
  
round_off_values = np.around(in_array)
print ("\nRounded values : \n", round_off_values)
  
  
in_array = [.53, 1.54, .71]
print ("\nInput array : \n", in_array)
  
round_off_values = np.around(in_array)
print ("\nRounded values : \n", round_off_values)
  
in_array = [.5538, 1.33354, .71445]
print ("\nInput array : \n", in_array)
  
round_off_values = np.around(in_array, decimals = 3)
print ("\nRounded values : \n", round_off_values)

输出 ：

Input array : 
 [0.5, 1.5, 2.5, 3.5, 4.5, 10.1]

Rounded values : 
 [  0.   2.   2.   4.   4.  10.]

Input array : 
 [0.53, 1.54, 0.71]

Rounded values : 
 [ 1.  2.  1.]

Input array : 
 [0.5538, 1.33354, 0.71445]

Rounded values : 
 [ 0.554  1.334  0.714]

代码 2：工作

# Python program explaining
# around() function
  
import numpy as np
  
in_array = [1 ,4, 7, 9, 12]
print ("Input array : \n", in_array)
  
round_off_values = np.around(in_array)
print ("\nRounded values : \n", round_off_values)
  
  
in_array = [133 ,344, 437, 449, 12]
print ("\nInput array : \n", in_array)
  
round_off_values = np.around(in_array, decimals = -2)
print ("\nRounded values upto 2: \n", round_off_values)
  
in_array = [133 ,344, 437, 449, 12]
print ("\nInput array : \n", in_array)
  
round_off_values = np.around(in_array, decimals = -3)
print ("\nRounded values upto 3: \n", round_off_values)

输出 ：

Input array : 
 [1, 4, 7, 9, 12]

Rounded values : 
 [ 1  4  7  9 12]

Input array : 
 [133, 344, 437, 449, 12]

Rounded values upto 2: 
 [100 300 400 400   0]

Input array : 
 [133, 344, 437, 449, 12]

Rounded values upto 3: 
 [0 0 0 0 0]

参考 ：
https://docs.scipy.org/doc/numpy-dev/reference/generated/numpy.around.html#numpy.around
.