NumPy: Check whether the dimensions of two given arrays are same or not

Last update on August 29 2025 12:48:46 (UTC/GMT +8 hours)

Check if dimensions of two arrays match.

Write a NumPy program to check whether the dimensions of two given arrays are same or not.

Pictorial Presentation:

Sample Solution:

Python Code:

# Importing the NumPy library
import numpy as np

# Defining a function to check array dimensions
def test_array_dimensions(ar1, ar2):
    try:
        # Attempting to add arrays ar1 and ar2
        ar1 + ar2
    except ValueError:
        # If ValueError occurs (arrays have different dimensions), return "Different dimensions"
        return "Different dimensions"
    else:
        # If no error occurs (arrays have the same dimensions), return "Same dimensions"
        return "Same dimensions"

# Creating two NumPy arrays: ar1 and ar2 reshaped into a 4x5 array
ar1 = np.arange(20).reshape(4, 5)
ar2 = np.arange(20).reshape(4, 5)

# Testing array dimensions for ar1 and ar2 using the defined function
print(test_array_dimensions(ar1, ar2))

# Creating two NumPy arrays: ar1 and ar2 reshaped into a 5x4 and 4x5 arrays respectively
ar1 = np.arange(20).reshape(5, 4)
ar2 = np.arange(20).reshape(4, 5)

# Testing array dimensions for ar1 and ar2 using the defined function
print(test_array_dimensions(ar1, ar2)) 

Sample Output:

Same dimensions
Different dimensions

Explanation:

The above code defines a function called 'test_array_dimensions()' that checks whether two input arrays have the same dimensions (i.e., can be added element-wise) and returns a string indicating the result.

• The function takes two input arguments, 'ar1' and 'ar2', which are NumPy arrays.
• A try block is used to attempt adding 'ar1' and 'ar2' element-wise using the + operator. If the dimensions of the arrays are compatible for addition, the operation will be executed without any issues.
• If the dimensions of the arrays are not compatible for addition, a ValueError will be raised. In this case, the code inside the except ValueError block will be executed, returning the string "Different dimensions".
• If the addition is successful and no ValueError is raised, the code inside the else block will be executed, returning the string "Same dimensions".

For more Practice: Solve these Related Problems:

• Write a NumPy program to compare the shapes of two arrays and return a boolean indicating if they have identical dimensions.
• Create a function that checks both the number of dimensions and the size of each dimension between two arrays.
• Implement a solution that uses the ndarray.shape attribute to determine dimension compatibility before an operation.
• Test the dimension matching function on arrays of varying shapes to verify its correctness.

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