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 geekprint("Is NaN : ", geek.isnan(1), "\n")print("Is NaN : ", geek.isnan(0), "\n")# not a numberprint("Is NaN : ", geek.isnan(geek.nan), "\n")# infinityprint("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 elementb = 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]]
References : https://docs.scipy.org/doc/numpy-dev/reference/generated/numpy.isnan.html
Note : These codes won’t run on online IDE’s. So please, run them on your systems to explore the working.
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