Creating sparse matrices in SciPy - Try It Yourself

Creating sparse matrices

📖 Scenario: Imagine you work with a large dataset where most values are zero. Storing all zeros wastes memory. Sparse matrices help save space by storing only non-zero values.

🎯 Goal: You will create a sparse matrix using the scipy.sparse library from a small dense matrix. This will help you understand how to efficiently store data with many zeros.

📋 What You'll Learn

Use the scipy.sparse library

Create a dense matrix as a list of lists

Create a sparse matrix from the dense matrix

Print the sparse matrix

💡 Why This Matters

🌍 Real World

Sparse matrices are used in machine learning, recommendation systems, and scientific computing where data has many zeros.

💼 Career

Knowing how to create and use sparse matrices helps you work efficiently with large datasets and optimize memory usage.

1

Create a dense matrix

Create a variable called dense_matrix and assign it a list of lists with these exact values: [[0, 0, 3], [4, 0, 0], [0, 5, 0]].

SciPy

# Create the dense matrix called dense_matrix
# Your code here

Need a hint?

Use square brackets to create a list of lists exactly as shown.

2

Import scipy sparse module

Import the csr_matrix class from the scipy.sparse module.

SciPy

dense_matrix = [[0, 0, 3], [4, 0, 0], [0, 5, 0]]
# Import csr_matrix from scipy.sparse
# Your code here

Need a hint?

Use from scipy.sparse import csr_matrix to import.

3

Create a sparse matrix

Create a variable called sparse_matrix by passing dense_matrix to csr_matrix().

SciPy

from scipy.sparse import csr_matrix

dense_matrix = [[0, 0, 3], [4, 0, 0], [0, 5, 0]]
# Create sparse_matrix from dense_matrix using csr_matrix
# Your code here

Need a hint?

Call csr_matrix(dense_matrix) and assign it to sparse_matrix.

4

Print the sparse matrix

Print the variable sparse_matrix to see its contents.

SciPy

from scipy.sparse import csr_matrix

dense_matrix = [[0, 0, 3], [4, 0, 0], [0, 5, 0]]
sparse_matrix = csr_matrix(dense_matrix)
# Print sparse_matrix
# Your code here

Need a hint?

Use print(sparse_matrix) to display the sparse matrix.