Hướng dẫn dùng percentiles explained python

numpy.percentile()function used to compute the nth percentile of the given data (array elements) along the specified axis. 
 

Syntax : numpy.percentile(arr, n, axis=None, out=None) 
Parameters : 
arr :input array. 
n : 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 :nth Percentile of the array (a scalar value if axis is none)or array with percentile values along specified axis. 
 

Code #1 : Working 
 

Python

import numpy as np

arr = [20, 2, 7, 1, 34]

print("arr : ", arr)

print("50th 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))

Output : 
 

arr : [20, 2, 7, 1, 34] 50th percentile of arr : 7.0 25th percentile of arr : 2.0 75th percentile of arr : 20.0

  
Code #2 : 
 

Python

import numpy as np

arr = [[14, 17, 12, 33, 44], 

       [15, 6, 27, 8, 19],

       [23, 2, 54, 1, 4,]]

print("\narr : \n", arr)

print("\n50th Percentile of arr, axis = None : ",

      np.percentile(arr, 50))

print("0th Percentile of arr, axis = None : ",

      np.percentile(arr, 0))

print("\n50th Percentile of arr, axis = 0 : ",

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

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

      np.percentile(arr, 0, axis =0))

Output : 
 

arr : [[14, 17, 12, 33, 44], [15, 6, 27, 8, 19], [23, 2, 54, 1, 4]] 50th Percentile of arr, axis = None : 15.0 0th Percentile of arr, axis = None : 1.0 50th Percentile of arr, axis = 0 : [15. 6. 27. 8. 19.] 0th Percentile of arr, axis = 0 : [14. 2. 12. 1. 4.] 50th Percentile of arr, axis = 1 : [17. 15. 4.] 0th Percentile of arr, axis = 1 : [12. 6. 1.]

Code #3 : 
 

Python

import numpy as np

arr = [[14, 17, 12, 33, 44], 

       [15, 6, 27, 8, 19],

       [23, 2, 54, 1, 4,]]

print("\narr : \n", arr)

print("\n50th Percentile of arr, axis = 1 : ",

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

print("0th Percentile of arr, axis = 1 : ",

      np.percentile(arr, 0, axis =1))

print("\n0th Percentile of arr, axis = 1 : \n",

      np.percentile(arr, 50, axis =1, keepdims=True))

print("\n0th Percentile of arr, axis = 1 : \n",

      np.percentile(arr, 0, axis =1, keepdims=True))

Output : 
 

arr : [[14, 17, 12, 33, 44], [15, 6, 27, 8, 19], [23, 2, 54, 1, 4]] 0th Percentile of arr, axis = 1 : [[17.] [15.] [ 4.]] 0th Percentile of arr, axis = 1 : [[12.] [ 6.] [ 1.]]