[Solved] Identify the error in the following code that attempts to create a Jacobi preconditioner:import numpy as np from scipy.sparse.linalg import LinearOperator A = np.... | SciPy

SciPy - Sparse Linear Algebra

Identify the error in the following code that attempts to create a Jacobi preconditioner:

import numpy as np
from scipy.sparse.linalg import LinearOperator

A = np.array([[3, 1], [1, 4]])
M = LinearOperator(shape=A.shape, matvec=lambda x: np.diag(A) * x)
print(M.matvec(np.array([1, 2])))

AUsing np.diag(A) incorrectly as a matrix

BMultiplying by diagonal instead of dividing

CShape of LinearOperator is wrong

DInput vector has wrong size

Step-by-Step Solution

Solution:

Step 1: Understand Jacobi preconditioner operation
Jacobi preconditioner divides vector elements by diagonal elements of A.
Step 2: Check given matvec function
Code multiplies vector by diagonal instead of dividing, which is incorrect.
Final Answer:
Multiplying by diagonal instead of dividing -> Option B
Quick Check:
Jacobi requires division, not multiplication [OK]

Quick Trick: Jacobi preconditioner divides vector by diagonal, not multiply [OK]

Common Mistakes:

Confusing multiplication with division
Ignoring element-wise operations
Not verifying mathematical definition

Master "Sparse Linear Algebra" in SciPy

9 interactive learning modes - each teaches the same concept differently

Learn Why Deep Visual Try Challenge Project Recall Time

More SciPy Quizzes

Identify the error in the following code that attempts to create a Jacobi preconditioner:

Step 1: Understand Jacobi preconditioner operation

Step 2: Check given matvec function

Final Answer:

Quick Check:

Want More Practice?