v Getting The Diagonal Of A Matrix - Machine Learning

Getting The Diagonal Of A Matrix

Preliminaries

# Load library
import numpy as np

Create Matrix

# Create matrix
matrix = np.array([[1, 2, 3],
                   [4, 5, 6],
                   [7, 8, 9]])

Get The Diagonal

# Return diagonal elements
matrix.diagonal()
array([1, 5, 9])

Calculate The Trace

# Calculate the tracre of the matrix
matrix.diagonal().sum()
15