NumPy: Compute the sum of the diagonal element of a given array

NumPy: Linear Algebra Exercise-15 with Solution

Write a NumPy program to compute the sum of the diagonal element of a given array.

Sample Solution:

Python Code :

# Importing the NumPy library
import numpy as np

# Create a 2x3 NumPy array 'm' using arange() and reshape()
m = np.arange(6).reshape(2, 3)

# Display the original matrix 'm'
print("Original matrix:")
print(m)

# Calculate the trace of the matrix 'm' using np.trace() function
result = np.trace(m)

# Display the trace of the matrix 'm'
print("Trace of the said matrix:")
print(result)

Sample Output:

Original matrix:
[[0 1 2]
 [3 4 5]]
Condition number of the said matrix:
4

Explanation:

In the above code –

m = np.arange(6).reshape(2,3): This line creates a 2x3 NumPy array m with elements from 0 to 5.

result = np.trace(m): This line attempts to compute the trace of the matrix m. However, it is important to note that the trace of a matrix is defined only for square matrices (i.e., matrices with the same number of rows and columns).

In this case, m is not a square matrix, so the trace is not properly defined. The numpy.trace function will still return a result, but it will only sum the diagonal elements that exist in the non-square matrix. In this case, the trace is the sum of the elements at indices (0, 0) and (1, 1), which is 0 + 4 = 4.

Python-Numpy Code Editor:

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