NumPy: Multiply a 5x3 matrix by a 3x2 matrix and create a real matrix product

Last update on August 29 2025 12:48:33 (UTC/GMT +8 hours)

11. Matrix Product of Real Numbers

Write a NumPy program to multiply a 5x3 matrix by a 3x2 matrix and create a real matrix product.

Sample Solution:

Python Code:

# Importing the NumPy library
import numpy as np

# Generating a random array of shape (5, 3)
x = np.random.random((5,3))

# Displaying the first array
print("First array:")
print(x)

# Generating another random array of shape (3, 2)
y = np.random.random((3,2))

# Displaying the second array
print("Second array:")
print(y)

# Computing the dot product of the two arrays
z = np.dot(x, y)

# Displaying the dot product of the arrays
print("Dot product of two arrays:")
print(z)

Sample Output:

First array:                                                           
[[ 0.44349753  0.81043761  0.00771825]                                 
 [ 0.64004088  0.86774612  0.19944667]                                 
 [ 0.61520091  0.24796788  0.93798297]                                 
 [ 0.22156999  0.61318856  0.82348994]                                 
 [ 0.91324026  0.13411297  0.00622696]]                                
Second array:                                                          
[[ 0.73873542  0.06448186]                                             
 [ 0.90974982  0.06409165]                                             
 [ 0.22321268  0.39147412]]                                            
Dot product of two arrays:                                             
[[ 1.06664562  0.08356133]                                             
 [ 1.30677176  0.17496452]                                             
 [ 0.88942914  0.42275803]                                             
 [ 0.90534318  0.37596252]                                             
 [ 0.79804212  0.06992065]]

Explanation:

In the above code –

The np.random.random() function creates an array of random numbers between 0 and 1 of the specified shape. In this case, x is a 5x3 array and y is a 3x2 array.

The np.dot() function takes two arrays and returns their dot product, which is the matrix multiplication of the two arrays. In this case, since the first array x has shape (5,3) and the second array y has shape (3,2), their dot product will have shape (5,2).

z = np.dot(x, y) - The resulting matrix z is the product of x and y and is a 5x2 array. The value in row i and column j of z is the dot product of row i of x and column j of y.

For more Practice: Solve these Related Problems:

Implement a function that multiplies a 5x3 matrix by a 3x2 matrix using np.dot and verifies the resulting dimensions.
Test the matrix multiplication on randomly generated matrices and compare the result with manual computation.
Compare the outputs of np.matmul and the @ operator on the same pair of matrices.
Perform matrix multiplication on integer matrices and ensure correct type conversion to floating point if necessary.

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