Python numpy.copysign()用法及代码示例

numpy.copysign(arr1，arr2，out = None，其中= True，强制转换=“ same_kind”，order =“ K”，dtype = None)：此数学函数可帮助用户更改arr1和arr2的符号。 arr1或arr2都可以是列表/序列或标量值。如果是顺序，则两者必须具有相同的尺寸；否则，arr2可以是一个标量值。

参数：
arr1 : [array_like]Input array, values to change sign of.
arr2 : [array_like]Input array, values to change sign of.
out : [ndarray, optional]Output array with same dimensions as Input array, placed with result.
**kwargs: Allows you to pass keyword variable length of argument to a function. It is used when we want to handle named argument in a function.
where : [array_like, optional]True value means to calculate the universal functions(ufunc) at that position, False value means to leave the value in the output alone.

返回： x1 with sign of x2.

代码1：

# Python program illustrating  
# copysign() method  
import numpy as np  
  
arr1 = [1, -23, +34, 11] 
arr2 = [-1, 2, -3, -4] 
  
print ("arr1:", arr1) 
print ("arr2:", arr2) 
  
print ("\nCheck sign of arr1:", np.signbit(arr1)) 
print ("\nCheck sign of arr2:", np.signbit(arr1)) 
print ("\nCheck for copysign:", np.signbit(np.copysign(arr1, arr2)))

输出：

arr1: [1, -23, 34, 11]
arr2: [-1, 2, -3, -4]

Check sign of arr1: [False  True False False]
Check sign of arr2: [False  True False False]
Check for copysign: [ True False  True  True]

代码2：

# Python program illustrating  
# copysign() method  
import numpy as np  
  
arr1 = [1, -23, +34, 11] 
  
print ("\nCheck sign of arr2:", np.signbit(arr1)) 
print ("\nCheck for copysign:", np.signbit(np.copysign(arr1, -3)))

输出：

Check sign of arr2: [False  True False False]
Check for copysign: [ True  True  True  True]