Matrix Multiplication in NumPy
Last Updated :
02 Sep, 2020
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Let us see how to compute matrix multiplication with NumPy. We will be using the numpy.dot() method to find the product of 2 matrices.
Python3 1==
Output :
Python3 1==
Output :
For example, for two matrices A and B. A = [[1, 2], [2, 3]] B = [[4, 5], [6, 7]] So, A.B = [[1*4 + 2*6, 2*4 + 3*6], [1*5 + 2*7, 2*5 + 3*7] So the computed answer will be: [[16, 26], [19, 31]]In Python numpy.dot() method is used to calculate the dot product between two arrays. Example 1 : Matrix multiplication of 2 square matrices.
# importing the module
import numpy as np
# creating two matrices
p = [[1, 2], [2, 3]]
q = [[4, 5], [6, 7]]
print("Matrix p :")
print(p)
print("Matrix q :")
print(q)
# computing product
result = np.dot(p, q)
# printing the result
print("The matrix multiplication is :")
print(result)
Matrix p : [[1, 2], [2, 3]] Matrix q : [[4, 5], [6, 7]] The matrix multiplication is : [[16 19] [26 31]]Example 2 : Matrix multiplication of 2 rectangular matrices.
# importing the module
import numpy as np
# creating two matrices
p = [[1, 2], [2, 3], [4, 5]]
q = [[4, 5, 1], [6, 7, 2]]
print("Matrix p :")
print(p)
print("Matrix q :")
print(q)
# computing product
result = np.dot(p, q)
# printing the result
print("The matrix multiplication is :")
print(result)
Matrix p : [[1, 2], [2, 3], [4, 5]] Matrix q : [[4, 5, 1], [6, 7, 2]] The matrix multiplication is : [[16 19 5] [26 31 8] [46 55 14]]
