C program to perform scalar matrix multiplication

Scalar matrix multiplication is a fundamental operation in linear algebra where each element of a matrix is multiplied by a scalar value. This operation is commonly used in various fields such as computer graphics, scientific computing, and engineering. In this article, we will guide you through writing a C program to perform scalar matrix multiplication, providing a detailed explanation and sample code.

What is Scalar Matrix Multiplication?

Scalar matrix multiplication involves taking a matrix and a scalar value, and then multiplying every element of the matrix by that scalar value. For example, if you have a 2x2 matrix:

and a scalar value (k) , the resulting matrix after scalar multiplication would be:

Each element of the original matrix is multiplied by the scalar (k).

Steps to Perform Scalar Matrix Multiplication

To perform scalar matrix multiplication in C, we can follow these steps:

1. Input the Matrix: Read the elements of the matrix from the user.
2. Input the Scalar: Read the scalar value from the user.
3. Perform the Multiplication: Multiply each element of the matrix by the scalar value.
4. Print the Result: Output the resultant matrix to the console.

Write a C program to perform scalar matrix multiplication

#include <stdio.h>

int main() {
    int rows, cols;
    float scalar;

    // Input the dimensions of the matrix
    printf("Enter the number of rows and columns of the matrix -\n");
    scanf("%d %d", &rows, &cols);

    // Declare the matrix
    float matrix[rows][cols];

    // Input elements of the matrix
    printf("Enter elements of the matrix -\n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("Element [%d][%d]: ", i, j);
            scanf("%f", &matrix[i][j]);
        }
    }

    // Input the scalar value
    printf("Enter the scalar value to multiply: ");
    scanf("%f", &scalar);

    // Perform scalar multiplication
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] *= scalar;
        }
    }

    // Print the resultant matrix
    printf("Resultant matrix after scalar multiplication:\n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%.2f ", matrix[i][j]);
        }
        printf("\n");
    }

    return 0;
}

Output

Enter the number of rows and columns of the matrix -
3
3
Enter elements of the matrix -
Element [0][0]: 1
Element [0][1]: 2
Element [0][2]: 3
Element [1][0]: 4
Element [1][1]: 5
Element [1][2]: 6
Element [2][0]: 7
Element [2][1]: 8
Element [2][2]: 9
Enter the scalar value to multiply: 3
Resultant matrix after scalar multiplication:
3.00 6.00 9.00
12.00 15.00 18.00
21.00 24.00 27.00

Explanation

1. Input the Matrix: The user inputs the dimensions (number of rows and columns) of the matrix and then enters the elements of the matrix.
2. Input the Scalar: The user inputs the scalar value by which the matrix elements will be multiplied.
3. Perform the Multiplication:
   • Nested loops iterate over each element of the matrix.
   • Each element of the matrix is multiplied by the scalar value and the result is stored in the same matrix.
4. Print the Result: The program prints the elements of the resultant matrix.

Detailed Steps

• Step 1: Input the Matrix
  • The program prompts the user to enter the number of rows and columns for the matrix.
  • The user inputs the elements of the matrix.
• Step 2: Input the Scalar
  • The program prompts the user to enter the scalar value for the multiplication.
• Step 3: Perform the Multiplication
  • Two nested loops iterate through each element of the matrix.
  • Each element is multiplied by the scalar value, and the result is stored back in the matrix.
• Step 4: Print the Result
  • The program prints the elements of the resultant matrix row by row.