Scalar matrix multiplication

Posted on Apr 25, 2020

C program to perform scalar matrix multiplication.

In matrix algebra, a real number is called a scalar. The scalar product of a real number s, and a matrix A is the matrix sA. In scalar multiplication of matrix, we simply multiply each element of the matrix by a scalar number.

For example, scalar (s) = 3

Program

#include<stdio.h>
#include<conio.h>
#define MAX 10

void main()
{
	int mat[MAX][MAX];
    int row, col;
    int i, j, num;

    printf("Enter the number of rows\t:");
    scanf("%d",&row);
    printf("Enter the number of columns\t:");
    scanf("%d",&col);

    printf("Enter the elements\n");
    for(i=0;i<row;i++)
    {
        for(j=0;j<col;j++)
        {
            printf("Element [%d][%d]\t:",i,j);
            scanf("%d",&mat[i][j]);
        }
    }

    printf("Enter the number to multiply with the matrix\t:");
    scanf("%d",&num);

    printf("\n\nMatrix entered is\n");
    for(i=0;i<row;i++)
    {
        for(j=0;j<col;j++)
        {
            printf("%d\t",mat[i][j]);
        }
        printf("\n");
    }

    for(i=0;i<row;i++)
    {
        for(j=0;j<col;j++)
        {
            mat[i][j] = num*mat[i][j];
        }
    }

    printf("\n\nMatrix after scalar multiplication\n");
    for(i=0;i<row;i++)
    {
        for(j=0;j<col;j++)
        {
            printf("%d\t",mat[i][j]);
        }
        printf("\n");
    }

    getch();
}

Output

Enter the number of rows        :3
Enter the number of columns     :4
Enter the elements
Element [0][0]  :1
Element [0][1]  :2
Element [0][2]  :3
Element [0][3]  :4
Element [1][0]  :5
Element [1][1]  :6
Element [1][2]  :7
Element [1][3]  :8
Element [2][0]  :9
Element [2][1]  :10
Element [2][2]  :11
Element [2][3]  :12
Enter the number to multiply with the matrix    :3


Matrix entered is
1       2       3       4
5       6       7       8
9       10      11      12


Matrix after scalar multiplication
3       6       9       12
15      18      21      24
27      30      33      36