# numpy.nanargmax() in Python

numpy.nanargmax(array, axis = None) : Returns indices of the max element of the array in a particular axis ignoring NaNs.
The results cannot be trusted if a slice contains only NaNs and Infs.
Parameters :

```array : Input array to work on
axis  : [int, optional]Along a specified axis like 0 or 1
```

Return :

```Array of indices into the array with same shape as array.shape
with the dimension along axis removed.```

Code 1 :

 `# Python Program illustrating ` `# working of nanargmax() ` ` `  `import` `numpy as geek  ` ` `  `# Working on 1D array ` `array ``=` `[geek.nan, ``4``, ``2``, ``3``, ``1``] ` `print``(``"INPUT ARRAY 1 : \n"``, array) ` ` `  `array2 ``=` `geek.array([[geek.nan, ``4``], [``1``, ``3``]]) ` ` `  `# returning Indices of the max element ` `# as per the indices ingnoring NaN ` `print``(``"\nIndices of max in array1 : "``, geek.nanargmax(array)) ` ` `  `# Working on 2D array ` `print``(``"\nINPUT ARRAY 2 : \n"``, array2) ` `print``(``"\nIndices of max in array2 : "``, geek.nanargmax(array2)) ` ` `  `print``(``"\nIndices at axis 1 of array2 : "``, geek.nanargmax(array2, axis ``=` `1``)) `

Output :

```INPUT ARRAY 1 :
[nan, 4, 2, 3, 1]

Indices of max in array1 :  1

INPUT ARRAY 2 :
[[ nan   4.]
[  1.   3.]]

Indices of max in array2 :  1

Indices at axis 1 of array2 :  [1 1]
```

Code 2 : Comparing working of argmax and nanargmax

 `# Python Program illustarting ` `# working of nanargmax() ` ` `  `import` `numpy as geek  ` ` `  `# Working on 2D array ` `array ``=` `( [[ ``8``, ``13``, ``5``, ``0``], ` `           ``[ ``16``, geek.nan, ``5``, ``3``], ` `           ``[geek.nan, ``7``, ``15``, ``15``], ` `           ``[``3``, ``11``, ``4``, ``12``]]) ` `print``(``"INPUT ARRAY : \n"``, array) ` ` `  `# returning Indices of the max element ` `# as per the indices  ` ` `  `'''    ` `   ``[[ 8 13  5  0] ` `   ``[ 16  2  5  3] ` `   ``[10  7 15 15] ` `   ``[ 3 11  4 12]] ` `     ``^  ^  ^  ^ ` `      `  `'''` ` `  `print``(``"\nIndices of max using argmax : "``, geek.argmax(array, axis ``=` `0``)) ` `print``(``"\nIndices of max using nanargmax :  : "``, geek.nanargmax(array, axis ``=` `0``)) `

Output :

```INPUT ARRAY :
[[8, 13, 5, 0], [16, nan, 5, 3], [nan, 7, 15, 15], [3, 11, 4, 12]]

Indices of max using argmax :  [2 1 2 2]

Indices of max using nanargmax :  :  [1 0 2 2]
```

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 contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.