lib/gen_voltcurmat.c


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#include "fracture.h"

cholmod_sparse *gen_voltcurmat(unsigned int num_edges, unsigned int num_verts,
															 unsigned int *edges_to_verts,
															 cholmod_common *c) {

	cholmod_triplet *t_m = CHOL_F(allocate_triplet)(
			num_edges, num_verts, num_edges * 2, 0, CHOLMOD_REAL, c);
	assert(t_m != NULL);

	int_t *rowind = (int_t *)t_m->i;
	int_t *colind = (int_t *)t_m->j;
	double *acoo = (double *)t_m->x;

	for (unsigned int i = 0; i < num_edges; i++) {
		unsigned int v1 = edges_to_verts[2 * i];
		unsigned int v2 = edges_to_verts[2 * i + 1];
		rowind[2 * i] = i;
		rowind[2 * i + 1] = i;
		colind[2 * i] = v1;
		colind[2 * i + 1] = v2;
		acoo[2 * i] = 1;
		acoo[2 * i + 1] = -1;
	}

	t_m->nnz = num_edges * 2;

	assert(CHOL_F(check_triplet)(t_m, c));

	cholmod_sparse *m = CHOL_F(triplet_to_sparse)(t_m, num_edges * 2, c);

	CHOL_F(free_triplet)(&t_m, c);

	return m;
}