How to allocate memory of a double pointer in a function?

Question

I am trying to allocate memory of a double pointer declared in main function:

int main () {

    float **a, **b, **c;

    inicializarMatriz (&a, &b, &c);
}

Inside inicializarMatriz function should malloc the matrix (double pointer).

void inicializarMatriz(float ***a, float ***b, float ***c) {
    // Reservar espacio de memoria para la matriz a
    **a = (float **) malloc ( N * sizeof(float *) );
    for (int i = 0; i < N; ++i) {
        a[i] = (float *) malloc ( N * sizeof(float) );
    }
    if ( a == NULL ) {
        fprintf(stderr, "No se ha podido asignar memoria a la matriz a");
    }

    // Reservar espacio de memoria para la matriz b
    **b = (float **) malloc ( N * sizeof(float *) );
    for (int i = 0; i < N; ++i) {
        b[i] = (float *) malloc ( N * sizeof(float) );
    }
    if ( b == NULL ) {
        fprintf(stderr, "No se ha podido asignar memoria a la matriz b");
    }

    // Reservar espacio de memoria para la matriz c
    **c = (float **) malloc ( N * sizeof(float *) );
    for (int i = 0; i < N; ++i) {
        c[i] = (float *) malloc ( N * sizeof(float) );
    }
    if ( c == NULL ) {
        fprintf(stderr, "No se ha podido asignar memoria a la matriz c");
    }
}

I have this warning: [Warning] assignment from incompatible pointer type and the program crashes. Any idea about what is wrong?

Answer 1

As @SomeProgrammerDude suggest, the working code is next:

int main () {

    float **a, **b, **c;

    inicializarMatriz (&a, &b, &c);
}

void inicializarMatriz(float ***a1, float ***b1, float ***c1) {
    // Reservar espacio de memoria para la matriz a
    *a1 = (float **) malloc ( N * sizeof(float *) ); // *a1 = **a
    for (int i = 0; i < N; ++i) {
        (*a1)[i] = (float *) malloc ( N * sizeof(float) ); // (*a1)[i] = a[i]
    }
    if ( a == NULL ) {
        fprintf(stderr, "No se ha podido asignar memoria a la matriz a");
    }

    // Reservar espacio de memoria para la matriz b
    *b1 = (float **) malloc ( N * sizeof(float *) ); // *b1 = **b
    for (int i = 0; i < N; ++i) {
        (*b1)[i] = (float *) malloc ( N * sizeof(float) ); // (*b1)[i] = b[i]
    }
    if ( b == NULL ) {
        fprintf(stderr, "No se ha podido asignar memoria a la matriz b");
    }

    // Reservar espacio de memoria para la matriz c
    *c1 = (float **) malloc ( N * sizeof(float *) ); // *c1 = **c
    for (int i = 0; i < N; ++i) {
        (*c1)[i] = (float *) malloc ( N * sizeof(float) ); // (*c1)[i] = c[i]
    }
    if ( c == NULL ) {
        fprintf(stderr, "No se ha podido asignar memoria a la matriz c");
    }
}

Solution of the problem is commeted inside the same line at the end.