NumPy: Get the n largest values of an array

NumPy: Random Exercise-16 with Solution

Write a NumPy program to get the n largest values of an array.

Sample Solution:

Python Code:

# Importing the NumPy library as np
import numpy as np

# Creating an array 'x' containing numbers from 0 to 9 using arange() function
x = np.arange(10)

# Displaying the original array 'x'
print("Original array:")
print(x)

# Shuffling the elements in array 'x'
np.random.shuffle(x)

# Selecting the 'n' largest elements in 'x' using argsort and slicing
n = 1
print(x[np.argsort(x)[-n:]]) 

Sample Output:

Original array:                                                        
[0 1 2 3 4 5 6 7 8 9]                                                  
[9]

Explanation:

In the above exercise –

x = np.arange(10): This statement generates a 1D array of integers from 0 to 9 (inclusive).

np.random.shuffle(x): This statement shuffles the elements of the array x in-place (i.e., the original array is modified) in a random order.

n = 1: This statement sets the variable n to 1, which represents the number of largest elements we want to extract from the shuffled array.

x[np.argsort(x)[-n:]]: This statement sorts the indices of the shuffled array x using np.argsort(x) in ascending order. Then, by slicing [-n:], we get the last n indices corresponding to the n largest elements in the array. In this case, since n = 1, the slice returns the index of the largest element in the shuffled array.

print(x[np.argsort(x)[-n:]]): Finally print() function prints the largest element in the shuffled array by indexing the array x with the calculated slice.

Pictorial Presentation:

Python-Numpy Code Editor:

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