# How to Perform Matrix Multiplication of given dimension in Python

In this Python tutorial, we will learn how to perform matrix multiplication in Python of any given dimension.

## MATRIX MULTIPLICATION in Python

Matrix multiplication is the multiplication of two matrices.

The necessary condition:

- R2(Number of Rows of the Second Matrix) = C1(Number of Columns of the First Matrix)
- Number of Rows of the Product Matrix =R1(Number of Rows of First Matrix)
- Number of Columns of the Product Matrix = C2(Number of Columns of the Second Matrix)

From the above conditions and the image we can understand that:

[A](m,n) X [B](n,s) = [P](m,s)

where

- m is the number of rows of A
- n is the number of columns of A = number of rows of B
- s is the number of columns of B

You may also learn,

- Matrix Transpose of a given Matrix of any dimension in Python
- How to perform Magic Square Operation in a Matrix using Python

Let’s take a look at the code snippet.

## Python program for matrix multiplication

r1=int(input("Enter number of Rows of Matrix A: ")) c1=int(input("Enter number of Columns of Matrix A: ")) A=[[0 for i in range(c1)] for j in range(r1)] #initialize matrix A print("Enter Matrix Elements of A:") #input matrix A for i in range(r1): for j in range(c1): x=int(input()) A[i][j]=x r2=int(input("Enter number of Rows of Matrix B: ")) c2=int(input("Enter number of Columns of Matrix B: ")) B=[[0 for i in range(c2)] for j in range(r2)] #initialize matrix B print("Enter Matrix Elements of B:") #input matrix B for i in range(r2): for j in range(c2): x=int(input()) B[i][j]=x if(c1==r2): #if no. of columns of matrix A is equal to no. of rows of matrix B P=[[0 for i in range(c2)] for j in range(r1)] #initialize product matrix for i in range(len(A)): for j in range(c2): for k in range(len(B)): P[i][j]=P[i][j]+(A[i][k]*B[k][j]) #multiplication #print the product matrix print("Product of Matrices A and B: ") for i in range(r1): for j in range(c2): print(P[i][j],end=" ") print() else: #if no. of columns of matrix A isn't equal to no. of rows of matrix B print("Matrix Multiplication is not possible.")

OUTPUT 1:

Enter number of Rows of Matrix A: 3 Enter number of Columns of Matrix A: 3 Enter Matrix Elements of A: 1 2 3 4 5 6 7 8 9 Enter number of Rows of Matrix B: 3 Enter number of Columns of Matrix B: 2 Enter Matrix Elements of B: 2 4 6 8 1 3 Product of Matrices A and B: 17 29 44 74 71 119

Here, the dimension of matrix A is 3X3. And the matrix B is of 3X2 dimension. Thus product matrix is 3X2.

OUTPUT 2:

Enter number of Rows of Matrix A: 4 Enter number of Columns of Matrix A: 3 Enter Matrix Elements of A: 4 8 6 7 8 2 1 4 5 6 7 3 Enter number of Rows of Matrix B: 3 Enter number of Columns of Matrix B: 2 Enter Matrix Elements of B: 7 5 6 4 3 3 Product of Matrices A and B: 94 70 103 73 46 36 93 67

The dimension of the Product matrix = (Number of rows of A) X (Number of columns of B)

Output 3:

Enter number of Rows of Matrix A: 3 Enter number of Columns of Matrix A: 3 Enter Matrix Elements of A: 7 8 6 9 4 3 5 1 2 Enter number of Rows of Matrix B: 2 Enter number of Columns of Matrix B: 2 Enter Matrix Elements of B: 4 5 2 6 Matrix Multiplication is not possible.

In this result, the number of rows of matrix B is not equal to the number of columns of matrix A. Thus the message shows that the matrix multiplication is not possible.

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