1. Python
  2. sciPy function stats.nanstd () | python

sciPy function stats.nanstd () | python



This is the formula —

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

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

Code # 1:

# standard deviation

import scipy

import numpy as np

 

arr1 = [ 1 , 3 , np.nan, 27 ] 

 

print ( "standard devi ation using nanstd: " , scipy.nanstd (arr1))

  

print ( "standard deviation without handling nan value:" , scipy.std (arr1)) 

Output: 

 standard deviation using nanstd: 11.813363431112899 standard deviation without handling nan value: nan

Code # 2 : with multidimensional data

# standard deviation

from scipy import std

from scipy import nanstd

import numpy as np

 

arr1 = [[ 1 , 3 , 27 ], 

[ 3 , np.nan, 6 ], 

[np.nan, 6 , 3 ], 

[ 3 , 6 , np.nan] ] 

 

print ( " standard deviation is: " , std (arr1)) 

print ( "standard deviation handling nan:" , nanstd (arr1)) 

 
# using axis = 0

print ( "standard deviation is with default axis = 0: " , 

  std (arr1, axis = 0 ))

print ( "standard deviation handling nan with default axis = 0: "< / code> , 

nanstd (arr1, axis = 0 ))

 
# using axis = 1

print ( "standard deviation is with default axis = 1:" , 

std (arr1, axis = 1 )) 

print ( "standard deviation handling nan with default axis = 1:" , 

nanstd (arr1, axis = 1  )) 

Output: 

 standard deviation is: nan standard deviation handling nan: 7.455216087651669 standard deviation is with default axis = 0: [nan nan nan] standard deviation handling nan with default axis = 0: [0.94280904 1.41421356 10.67707825] standard deviation is with default axis = 1: [11.81336343 nan nan nan] standard deviation handling nan with default axis = 1: [11.81336343 1.5 1.5 1.5]