# sciPy stats.nanmean() function | Python

• Last Updated : 11 Feb, 2019

`scipy.stats.nanmean(array, axis=0)` function calculates the arithmetic mean by ignoring the Nan (not a number) values of the array elements along the specified axis of the array.

It’s formula –

Parameters :
array : Input array or object having the elements, including Nan values, to calculate the arithmetic mean.
axis : Axis along which the mean is to be computed. By default axis = 0.

Returns : Arithmetic mean of the array elements (ignoring the Nan values) based on the set parameters.

Code #1:

 `# Arithmetic Mean ``import` `scipy``import` `numpy as np`` ` `arr1 ``=` `[``1``, ``3``, np.nan, ``27``] ``  ` `print``(``"Arithmetic Mean using nanmean :"``, scipy.nanmean(arr1))`` ` `print``(``"Arithmetic Mean without handling nan value :"``, scipy.mean(arr1)) `

Output :

```Arithmetic Mean using nanmean : 10.333333333333334
Arithmetic Mean without handling nan value : nan```

Code #2: With multi-dimensional data

 `# Arithmetic Mean ``from` `scipy ``import` `mean``from` `scipy ``import` `nanmean``import` `numpy as np`` ` `arr1 ``=` `[[``1``, ``3``, ``27``], ``        ``[``3``, np.nan, ``6``], ``        ``[np.nan, ``6``, ``3``], ``        ``[``3``, ``6``, np.nan]] ``  ` `print``(``"Arithmetic Mean is :"``, mean(arr1)) ``print``(``"Arithmetic Mean handling nan :"``, nanmean(arr1)) `` ` `# using axis = 0``print``(``"\nArithmetic Mean is with default axis = 0 : \n"``, ``      ``mean(arr1, axis ``=` `0``))``print``(``"\nArithmetic Mean handling nan with default axis = 0 : \n"``, ``      ``nanmean(arr1, axis ``=` `0``))`` ` `# using axis = 1``print``(``"\nArithmetic Mean is with default axis = 1 : \n"``, ``      ``mean(arr1, axis ``=` `1``))  ``print``(``"\nArithmetic Mean handling nan with default axis = 1 : \n"``, ``      ``nanmean(arr1, axis ``=` `1``))  `

Output :

```Arithmetic Mean is : nan
Arithmetic Mean handling nan : 6.444444444444445

Arithmetic Mean is with default axis =0 :
[nan nan nan]

Arithmetic Mean handling nan with default axis =0 :
[ 2.33333333  5.         12.        ]

Arithmetic Mean is with default axis =1 :
[10.33333333         nan         nan         nan]

Arithmetic Mean handling nan with default axis =1 :
[10.33333333  4.5         4.5         4.5       ]```

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