The numpy.isnan() function tests element-wise whether it is NaN or not and returns the result as a boolean array. Syntax :
numpy.isnan(array [, out])
Parameters :
array : [array_like]Input array or object whose elements, we need to test for infinity out : [ndarray, optional]Output array placed with result. Its type is preserved and it must be of the right shape to hold the output.
Return :
boolean array containing the result. For scalar input, the result is a new boolean with value True if the input is positive or negative infinity; otherwise the value is False. For array input, the result is a boolean array with the same shape as the input and the values are True where the corresponding element of the input is positive or negative infinity; elsewhere the values are False.
Code 1 :
Python
# Python Program illustrating # numpy.isnan() method import numpy as geek
print ( "Is NaN : " , geek.isnan( 1 ), "\n" )
print ( "Is NaN : " , geek.isnan( 0 ), "\n" )
# not a number print ( "Is NaN : " , geek.isnan(geek.nan), "\n" )
# infinity print ( "Is NaN : " , geek.isnan(geek.inf), "\n" )
print ( "Is NaN : " , geek.isnan(geek.NINF), "\n" )
x = geek.array([ - geek.inf, 0. , geek.inf])
y = geek.array([ 2 , 2 , 2 ])
print ( "Checking for NaN : " , geek.isnan(x, y))
|
Output :
Is NaN : False Is NaN : False Is NaN : True Is NaN : False Is NaN : False Checking for NaN : [0 0 0]
Code 2 :
Python
# Python Program illustrating # numpy.isnan() method import numpy as geek
# Returns True/False value for each element b = geek.arange( 20 ).reshape( 5 , 4 )
print ( "\n" ,b)
print ( "\nIs NaN(Not a Number): \n" , geek.isnan(b))
b = [[ 1j ],
[geek.nan]]
print ( "\nIs NaN(Not a Number) : \n" , geek.isnan(b))
|
Output :
[[ 0 1 2 3] [ 4 5 6 7] [ 8 9 10 11] [12 13 14 15] [16 17 18 19]] Is NaN(Not a Number): [[False False False False] [False False False False] [False False False False] [False False False False] [False False False False]] Is NaN(Not a Number) : [[False] [ True]]
Note : These codes won’t run on online IDE’s. So please, run them on your systems to explore the working.