Python中的 numpy.signbit()

numpy.signbit(array, out = None, where = True, casting = 'same_kind', order = 'K', dtype = None) ：这个数学函数帮助用户对元素进行检查——明智地检查符号位是否设置。

Parameters :
array : [array_like]Input array or object whose elements, we need to check.
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.

Return : True, if sign-bit is set; else False.

代码 ：

# Python program illustrating 
# signbit() method 
  
import numpy as np 
  
arr = [1, -23, +34, 11]
print ("arr : ", arr)
  
print ("\nCheck for signbit : ", np.signbit(arr))
  
out_arr = np.arange(4)
print ("\nout_arr : ", out_arr)
  
np.signbit(arr, out = out_arr)
  
print ("\nplacing signbit check values to out_arr : ", out_arr)

输出 ：

arr :  [1, -23, 34, 11]

Check for signbit :  [False  True False False]

out_arr :  [0 1 2 3]

placing signbit check values to out_arr :  [0 1 0 0]