NumPy: Change the dimension of an array

NumPy: Array Object Exercise-35 with Solution

Write a NumPy program to change an array's dimension.

Pictorial Presentation:

Sample Solution:

Python Code:

# Importing the NumPy library with an alias 'np'
import numpy as np

# Creating a NumPy array with 6 elements
x = np.array([1, 2, 3, 4, 5, 6])
# Printing the shape of the array (6 rows and 0 columns)
print("6 rows and 0 columns")
print(x.shape)

# Creating a 2D array (3x3 matrix)
y = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
# Printing the shape and content of the array (3 rows and 3 columns)
print("(3, 3) -> 3 rows and 3 columns ")
print(y)

# Creating a 1D array with 9 elements
x = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9])
# Changing the shape of the array to (3, 3) -> 3 rows and 3 columns
x.shape = (3, 3)
# Printing the array after changing its shape
print("Change array shape to (3, 3) -> 3 rows and 3 columns ")
print(x) 

Sample Output:

6 rows and 0 columns                                                   
(6,)                                                                   
(3, 3) -> 3 rows and 3 columns                                         
[[1 2 3]                                                               
 [4 5 6]                                                               
 [7 8 9]]                                                              
Change array shape to (3, 3) -> 3 rows and 3 columns                   
[[1 2 3]                                                               
 [4 5 6]                                                               
 [7 8 9]] 

Explanation:

In the above code -

x = np.array([1, 2, 3, 4, 5, 6]): The present line creates a one-dimensional NumPy array ‘x’ with elements from 1 to 6.

y = np.array([[1, 2, 3],[4, 5, 6],[7,8,9]]): The present line creates a two-dimensional NumPy array ‘y’ of shape (3, 3) with elements from 1 to 9.

x = np.array([1,2,3,4,5,6,7,8,9]): The present line reassigns ‘x’ to a new one-dimensional NumPy array with elements from 1 to 9.

x.shape = (3, 3): The present line reshapes the one-dimensional ‘x’ array into a two-dimensional array of shape (3, 3) by modifying its shape attribute directly.

print(x): Finally print() function prints the reshaped ‘x’ array, which now has the same shape and elements as the ‘y’ array.

Python-Numpy Code Editor:

Previous: Write a NumPy program to create an array of ones and an array of zeros.
Next: Write a NumPy program to create a contiguous flattened array.