numpy.sign () in Python



The numpy.sign (array [, out]) function is used to indicate the sign of a number element by element. 
For integer inputs, if the array value is greater than 0, 1 is returned, if the array value is less than 0, -1 is returned, and if the array value is 0, 0.

Syntax: numpy.sign ()

Parameters:
array: [array_like] Input values.
out: [ndarray, optional] Output array placed with result.

Return: [ndarray] Returns the sign of array. If an array is scalar then the sign of array will be scalar.

Code 1:

# Python program illustrating
# numpy.sign () method

  
# numpy import

import numpy as geek 

  
# input arrays

array1 = [ 1 , 0 , - 13 ]

array2 =   [ - 1 , 0 , 15 ]

 
# print input arrays

print ( "input array1:" , array1)

print ( "input array2: " , array2)

  
# define the sign of integers in the array

print ( "Check sign of array1:" , geek.sign (array1))

print  ( "Check sign of array2:" , geek.sign (array2)) 

Output:

 array1: [1, 0 , -13] array2: [-1, 0, 15] Check sign of array1: [1 0 -1] Check sign of array2: [-1 0 1] 

Code 2:

# Python program illustrating
# numpy.sign () method

 
# numpy import

import numpy as geek 

 
# define complex number sign

print ( "Check sign of complex input1:" , geek.sign ( 7 - 3j ))

print ( "Check sign of complex input2:" , geek.sign ( - 7 + 3j ) ) 

Output:

 Check sign of complex input1: (1 + 0j) Check sign of complex input2: (-1 + 0j)