Related Articles

# numpy.isinf() in Python

• Difficulty Level : Basic
• Last Updated : 06 Aug, 2021

The numpy.isinf() function tests element-wise whether it is +ve or -ve infinity or not return the result as a boolean array.

`Syntax: numpy.isinf(array [, out])`

Parameters :

Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning - Basic Level Course

```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.isinf() method`` ` `import` `numpy as geek` `print``(``"Finite : "``, geek.isinf(``1``), ``"\n"``)` `print``(``"Finite : "``, geek.isinf(``0``), ``"\n"``)` `# not a number``print``(``"Finite : "``, geek.isinf(geek.nan), ``"\n"``)` `#  infinity``print``(``"Finite : "``, geek.isinf(geek.inf), ``"\n"``)` `print``(``"Finite : "``, geek.isinf(geek.NINF), ``"\n"``)` `x ``=` `geek.array([``-``geek.inf, ``0.``, geek.inf])``y ``=` `geek.array([``2``, ``2``, ``2``])``print``(``"Checking for infinity : "``, geek.isinf(x, y))`

Output :

```Finite :  False

Finite :  False

Finite :  False

Finite :  True

Finite :  True

Checking for infinity :  [1 0 1]```

Code 2 :

## Python

 `# Python Program illustrating``# numpy.isinf() method``  ` `import` `numpy as geek`` ` `# Returns True/False value for each element``b ``=` `geek.arange(``8``).reshape(``2``, ``4``)``               ` `print``(``"\n"``,b)``print``(``"\nIs Infinity : \n"``, geek.isinf(b))` `# geek.inf  : Positive Infinity``# geek.NINF : negative Infinity``b ``=` `[[geek.inf],``     ``[geek.NINF]]``print``(``"\nIs Infinity : \n"``, geek.isinf(b))`

Output :

``` [[0 1 2 3]
[4 5 6 7]]

Is Infinity :
[[False False False False]
[False False False False]]

Is Infinity :
[[ True]
[ True]]```

Note :
These codes won’t run on online-ID. Please run them on your systems to explore the working.

This article is contributed by Mohit Gupta_OMG 😀. If you like GeeksforGeeks and would like to contribute, you can also write an article using write.geeksforgeeks.org or mail your article to review-team@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.