i was thinking about the way to make matrices in C, that ensures matrix types (Matrix2x2, Matrix3x3, …) and provides operations (Add, Substract, Multiply, Transpose). I found two methods.

First Method

I thought of implementing matrices as macros that construct arrays depending on the number of rows and columns.

I also made macros for constructing operations.

#define MATRIX_DEFINE(ROWS, COLUMNS) typedef float Matrix##ROWS##x##COLUMNS##[ROWS][COLUMNS]

MATRIX_DEFINE(2, 2);
MATRIX_DEFINE(3, 3);
MATRIX_DEFINE(4, 4);

#define MATRIX_ADD(ROWS, COLUMNS) ...
#define MATRIX_SUBSTRACT(ROWS, COLUMNS) ...
#define MATRIX_MULTIPLY(R1, C1, R2, C2) ...
#define MATRIX_TRANSPOSE(ROWS, COLUMNS) ...

I found that this method gives me more control and offers a more explicit way of operations.

I Also heard that hard-coding operations is more efficient that using dynamic memory allocation (Hence the use of macros).

Second Method

This is the dynamic approach and it goes as follows:

typedef struct {
    int rows;
    int cols;
    double **data;
} Matrix;

Matrix createMatrix(int rows, int cols) {
    Matrix matrix;
    matrix.rows = rows;
    matrix.cols = cols;
    matrix.data = (double **)malloc(rows * sizeof(double *));
    for (int i = 0; i < rows; i++) {
        matrix.data[i] = (double *)malloc(cols * sizeof(double));
    }
    return matrix;
}

void freeMatrix(Matrix matrix) {
    for (int i = 0; i < matrix.rows; i++) {
        free(matrix.data[i]);
    }
    free(matrix.data);
}

Matrix multiplyMatrices(Matrix a, Matrix b) {
    if (a.cols != b.rows) {
        fprintf(stderr, "Matrix dimensions do not match for multiplicationn");
        exit(EXIT_FAILURE);
    }

    Matrix result = createMatrix(a.rows, b.cols);

    for (int i = 0; i < a.rows; i++) {
        for (int j = 0; j < b.cols; j++) {
            result.data[i][j] = 0;
            for (int k = 0; k < a.cols; k++) {
                result.data[i][j] += a.data[i][k] * b.data[k][j];
            }
        }
    }

    return result;
}

...

I don’t know which approach i should go with and i would love some advice from you.