Sometimes we need to find the sum of the Upper right, Upper left, Lower right, or lower left diagonal elements. Numpy provides us the facility to compute the sum of different diagonals elements using numpy.trace() and numpy.diagonal() method.
Method 1: Finding the sum of diagonal elements using numpy.trace()
Syntax : numpy.trace(a, offset=0, axis1=0, axis2=1, dtype=None, out=None)
Example 1: For 3X3 Numpy matrix
Python3
# importing Numpy package import numpy as np # creating a 3X3 Numpy matrix n_array = np.array([[55, 25, 15], [30, 44, 2], [11, 45, 77]]) # Displaying the Matrix print("Numpy Matrix is:") print(n_array) # calculating the Trace of a matrix trace = np.trace(n_array) print("\nTrace of given 3X3 matrix:") print(trace) |
Output:
Example 2: For 4X4 Numpy matrix
Python3
# importing Numpy package import numpy as np # creating a 4X4 Numpy matrix n_array = np.array([[55, 25, 15, 41], [30, 44, 2, 54], [11, 45, 77, 11], [11, 212, 4, 20]]) # Displaying the Matrix print("Numpy Matrix is:") print(n_array) # calculating the Trace of a matrix trace = np.trace(n_array) print("\nTrace of given 4X4 matrix:") print(trace) |
Output:
Method 2: Finding the sum of diagonal elements using numpy.diagonal()
Syntax :
numpy.diagonal(a, offset=0, axis1=0, axis2=1
Example 1: For 3X3 Numpy Matrix
Python3
# importing Numpy package import numpy as np # creating a 3X3 Numpy matrix n_array = np.array([[55, 25, 15], [30, 44, 2], [11, 45, 77]]) # Displaying the Matrix print("Numpy Matrix is:") print(n_array) # Finding the diagonal elements of a matrix diag = np.diagonal(n_array) print("\nDiagonal elements are:") print(diag) print("\nSum of Diagonal elements is:") print(sum(diag)) |
Output:
Example 2: For 5X5 Numpy Matrix
Python3
# importing Numpy package import numpy as np # creating a 5X5 Numpy matrix n_array = np.array([[5, 2, 1, 4, 6], [9, 4, 2, 5, 2], [11, 5, 7, 3, 9], [5, 6, 6, 7, 2], [7, 5, 9, 3, 3]]) # Displaying the Matrix print("Numpy Matrix is:") print(n_array) # Finding the diagonal elements of a matrix diag = np.diagonal(n_array) print("\nDiagonal elements are:") print(diag) print("\nSum of Diagonal elements is:") print(sum(diag)) |
Output:
