numpy.nanpercentile () in Python

Michael Zippo 18.07.2021

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numpy.nanpercentile() used to calculate the nth percentile of data (array elements) along the specified axis, ang ignores nan values.

Syntax: numpy.nanpercentile (arr, q, axis = None, out = None)
Parameters:
arr: input array.
q: percentile value.
axis: axis along which we want to calculate the percentile value.Otherwise, it will consider arr to be flattened (works on all the axis). axis = 0
means along the column and axis = 1 means working along the row.
out: Different array in which we want to place the result. The array must have same dimensions as expected output.

Return: Percentile of the array (a scalar value if axis is none) or array with percentiles of values ‚Äã‚Äãalong specified axis.

Code # 1: Work

# Python program illustrating
# numpy.nanpercentile () method

import numpy as np

# 1D array

arr = [ 20 , 2 , 7 , np.nan, 34 ]

print ( " arr: " , arr)

print ( " 30th percentile of arr: " ,

np.percentile (arr, 50 ))

print ( "25th percentile of arr:" ,

np.percentile (arr, 25 ))

print ( "75th percentile of arr:" ,

np.percentile (arr, 75 ))

print ( "30th percentile of arr:" ,

np.nanpercentile (arr, 50 ))

print ( "25th percentile of arr:" ,

np.nanpercentile (arr, 25 ))

print ( "75th percentile of arr:" ,

n p.nanpercentile (arr, 75 ))

Output:

 arr: [20, 2, 7, nan, 34] 30th percentile of arr: nan 25th percentile of arr: nan 75th percentile of arr: nan 30th percentile of arr: 13.5 25th percentile of arr: 5.75 75th percentile of arr: 23.5

Code # 2:

       # Python program illustrating  
  # numpy.nanpercentile () method 
  
   import   numpy as np 
    
  # 2D array   
  arr   =   [[  14  , np.nan,   12  ,   33  ,   44  ],  
   [  15  , np.nan,   27  ,   8  ,   19  ], 
   [  23  ,   2  , np.nan,   1  ,   4  ,]] 
   print   (  "arr:"  , arr)  
    
  # Flattened array percentile  
   print   (  "50th Percentile of arr, axis = None:"  ,   
  np.percentile (arr,   50  )) 
   print   ( " 50th Percentile of arr, axis = None: " , 
     np.nanpercentile (arr,   50  ))  
   print   (  "0th Percentile of arr, axis = None:"  , 
   np.nanpercentile (arr,   0  )) 
  
  # Axis percentile = 0  
   print   (  "50th Percentile of arr, axis = 0:"  , 
   np.nanpercentile (arr,   50  , axis   =   0  )) 
   print   (  "0th Percentile of arr, axis = 0:"  , 
   np.nanpercentile (arr,   0  , axis   =   0  )) 
    
  # Axis percentile = 1  
   print   (  "50th Percentile of arr, axis = 1:"  ,  
   np.nanpercentile (arr,   50  , axis   =   1  ) ) 
   print   (  "0th Percentile of arr, axis = 1: " , 
     np.nanpercentile (arr,   0  , axis   =   1  )) 
   
  print   (  "0th Percentile of arr, axis = 1:"  ,   
  np.nanpercentile (arr,   50  , axis   =   1  , keepdims   =   True  )) 
   print   (  "0th Percentile of arr, axis = 1:"  , 
   np.nanpercentile (arr,   0  , axis   =   1  , keepdims   =   True   ))

Output:

 arr: [[14, nan, 12, 33, 44], [15, nan, 27, 8, 19], [23, 2, nan, 1, 4]] 50th Percentile of arr , axis = None: nan 50th Percentile of arr, axis = None: 14.5 0th Percentile of arr, axis = None: 1.0 50th Percentile of arr, axis = 0: [15. 2. 19.5 8. 19.] 0th Percentile of arr, axis = 0: [14. 2. 12. 1. 4.] 50th Percentile of arr, axis = 1: [23.5 17. 3.] 0th Percentile of arr, axis = 1: [12. 8. 1.] 0th Percentile of arr, axis = 1: [[23.5] [17. ] [3.]] 0th Percentile of arr, axis = 1: [[12.] [8.] [1.]]

Code # 3:

# Python program illustrating
# numpy.nanpercentile () method

import numpy as np

# 2D array

arr = [[ 14 , np.nan, 12 , 33 , 44 ],

[ 15 , np.nan, 27 , 8 , 19 ],

[ 23 , np.nan, np.nan, 1 , 4 ,]]

print ( "arr:" , arr )

# Axis percentile = 1

print ( "50th Percentile of arr, axis = 1:" ,

np.nanpercentile (arr, 50 , axis = 1 ))

print ( " 50th Percentile of arr, axis = 0: " ,

np.nanpercentile (arr, 50 , axis = 0 ))

Output:

 arr: [[14, nan, 12, 33, 44] , [15, nan, 27, 8, 19], [23, nan, nan, 1, 4]] 50th Percentile of arr, axis = 1: [23.5 17. 4.] 50th Percentile of arr, axis = 0: [fifteen. nan 19.5 8. 19.] RuntimeWarning: All-NaN slice encountered overwrite_input, interpolation)

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Ken Danburry

San Francisco | 2023-03-21

I was preparing for my coding interview, thanks for clarifying this - numpy.nanpercentile () in Python in Python is not the simplest one. Checked yesterday, it works!

Walter Innsbruck

Moscow | 2023-03-21

Simply put and clear. Thank you for sharing. numpy.nanpercentile () in Python and other issues with Expect PHP module was always my weak point 😁. Will get back tomorrow with feedback

Xu Richtgofen

Rome | 2023-03-21

I was preparing for my coding interview, thanks for clarifying this - numpy.nanpercentile () in Python in Python is not the simplest one. I just hope that will not emerge anymore