CSC format (Compressed Sparse Column) in SciPy - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the CSC matrix class from scipy.

SciPy

from scipy.sparse import [1]

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Acsr_matrix

Bdok_matrix

Ccsc_matrix

Dcoo_matrix

Attempts:

3 left

💡 Hint

Common Mistakes

Importing csr_matrix instead of csc_matrix

Using coo_matrix which is a different sparse format

The csc_matrix class is used to create and work with Compressed Sparse Column matrices in scipy.

2fill in blank

medium

Complete the code to create a 3x3 CSC matrix with data [1, 2, 3] at positions (0,0), (1,1), and (2,2).

SciPy

from scipy.sparse import csc_matrix
import numpy as np
row = np.array([0, 1, 2])
col = np.array([0, 1, 2])
data = np.array([1, 2, 3])
matrix = csc_matrix(([1], (row, col)), shape=(3, 3))

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Arow

Bdata

Ccol

D[1, 2, 3]

Attempts:

3 left

💡 Hint

Common Mistakes

Passing row or col arrays instead of data

Passing a list instead of the data variable

The first argument to csc_matrix is the data array containing the nonzero values.

3fill in blank

hard

Fix the error in the code to convert a dense numpy array to a CSC matrix.

SciPy

import numpy as np
from scipy.sparse import csc_matrix
dense = np.array([[0, 1], [2, 0]])
sparse = [1](dense)

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Acsr_matrix

Bdok_matrix

Ccoo_matrix

Dcsc_matrix

Attempts:

3 left

💡 Hint

Common Mistakes

Using csr_matrix instead of csc_matrix

Trying to call a method that does not exist

To convert a dense array to a CSC matrix, use csc_matrix constructor.

4fill in blank

hard

Fill both blanks to create a CSC matrix and then get its shape.

SciPy

from scipy.sparse import [1]
import numpy as np
data = np.array([4, 5, 6])
row = np.array([0, 1, 2])
col = np.array([0, 1, 2])
matrix = [2]((data, (row, col)), shape=(3, 3))
shape = matrix.shape

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Acsc_matrix

Bcsr_matrix

Ccoo_matrix

Ddok_matrix

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing import and constructor classes

Using csr_matrix or other formats

Both blanks require csc_matrix to create the matrix and import the class.

5fill in blank

hard

Fill all three blanks to create a CSC matrix, convert it to dense, and print the result.

SciPy

from scipy.sparse import [1]
data = [7, 8, 9]
row = [0, 1, 2]
col = [0, 1, 2]
matrix = [2]((data, (row, col)), shape=(3, 3))
dense_matrix = matrix.[3]()
print(dense_matrix)

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Acsc_matrix

Ctoarray

Dtodense

Attempts:

3 left

💡 Hint

Common Mistakes

Using toarray() instead of todense()

Importing wrong sparse matrix class

Import and create the CSC matrix with csc_matrix. To convert to dense, use todense() method.