NumPy: Reverse an array
Reverse Array
Write a NumPy program to reverse an array (the first element becomes the last).
Sample Solution:
Python Code:
# Importing the NumPy library with an alias 'np'
import numpy as np
# Creating an array 'x' using arange() function with values from 12 to 37 (inclusive)
x = np.arange(12, 38)
# Printing the original array 'x' containing values from 12 to 37
print("Original array:")
print(x)
# Reversing the elements in the array 'x' and printing the reversed array
print("Reverse array:")
x = x[::-1]
print(x)
Sample Output:
Original array: [12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37] Reverse array: [37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12]
Explanation:
In the above code -
np.arange(12, 38): Creates a one-dimensional NumPy array with a range of integers starting from 12 (inclusive) up to, but not including, 38. The result will be an array of length 26 containing integers from 12 to 37.
x = x[::-1]: Reverses the order of the elements in the NumPy array ‘x’ by using slice notation with a step of -1. The result will be a new NumPy array with the elements in the reverse order.
Python-Numpy Code Editor: