NumPy: Stack arrays in sequence vertically
Stack Arrays Vertically
Write a NumPy program to stack arrays vertically.
Pictorial Presentation:
Sample Solution:
Python Code:
# Importing the NumPy library and aliasing it as 'np'
import numpy as np
# Printing a message indicating the original arrays will be displayed
print("\nOriginal arrays:")
# Creating a 3x3 NumPy array 'x' with elements from 0 to 8 using np.arange() and reshaping it
x = np.arange(9).reshape(3, 3)
# Creating another 3x3 NumPy array 'y' by multiplying each element of 'x' by 3
y = x * 3
# Printing a message for Array-1 and displaying the original 3x3 array 'x'
print("Array-1")
print(x)
# Printing a message for Array-2 and displaying the modified 3x3 array 'y' (each element multiplied by 3)
print("Array-2")
print(y)
# Stacking Array-1 'x' and Array-2 'y' vertically using np.vstack()
new_array = np.vstack((x, y))
# Printing a message indicating the vertical stacking of arrays and displaying the new vertically stacked array
print("\nStack arrays in sequence vertically:")
print(new_array)
Sample Output:
Original arrays: Array-1 [[0 1 2] [3 4 5] [6 7 8]] Array-2 [[ 0 3 6] [ 9 12 15] [18 21 24]] Stack arrays in sequence vertically: [[ 0 1 2] [ 3 4 5] [ 6 7 8] [ 0 3 6] [ 9 12 15] [18 21 24]]
Explanation:
In the above code -
x = np.arange(9).reshape(3,3): This line creates an array with values from 0 to 8 (9 values) using np.arange(9), and then reshapes it into a 3x3 array using reshape(3,3).
y = x*3: It performs element-wise multiplication of the x array by 3.
new_array = np.vstack((x, y)): It vertically stacks the two 3x3 arrays x and y, resulting in a new 6x3 array new_array:
Finally, print() function prints the vertically stacked new_array.
Python-Numpy Code Editor: