int main(void) {
igraph_real_t avg_path;
igraph_t graph;
igraph_vector_t dimvector;
igraph_vector_t edges;
int i;
igraph_vector_init(&dimvector, 2);
VECTOR(dimvector)[0]=30;
VECTOR(dimvector)[1]=30;
igraph_lattice(&graph, &dimvector, 0, IGRAPH_UNDIRECTED, 0, 1);
igraph_rng_seed(igraph_rng_default(), 42);
igraph_vector_init(&edges, 20);
for (i=0; i<igraph_vector_size(&edges); i++) {
VECTOR(edges)[i] = rand() % (int)igraph_vcount(&graph);
}
igraph_average_path_length(&graph, &avg_path, IGRAPH_UNDIRECTED, 1);
printf("Average path length (lattice): %f\n", (double) avg_path);
igraph_add_edges(&graph, &edges, 0);
igraph_average_path_length(&graph, &avg_path, IGRAPH_UNDIRECTED, 1);
printf("Average path length (randomized lattice): %f\n", (double) avg_path);
igraph_vector_destroy(&dimvector);
igraph_vector_destroy(&edges);
igraph_destroy(&graph);
return 0;
}
int check_lattice(const lat_test_t *test) {
igraph_t graph, othergraph;
igraph_vector_t otheredges;
igraph_vector_t dimvector;
igraph_bool_t iso;
int ret;
/* Create lattice */
igraph_vector_view(&dimvector, test->dimedges, test->dim);
igraph_lattice(&graph, &dimvector, test->nei, test->directed,
test->mutual, test->circular);
/* Check its properties */
if ((ret=check_lattice_properties(&graph, &dimvector, test->directed,
test->mutual, test->circular))) {
igraph_destroy(&graph);
printf("Lattice properties are not satisfied\n");
return ret;
}
/* Check that it is isomorphic to the stored graph */
igraph_vector_view(&otheredges, test->dimedges+test->dim, test->m * 2);
igraph_create(&othergraph, &otheredges, igraph_vector_prod(&dimvector),
test->directed);
igraph_isomorphic(&graph, &othergraph, &iso);
if (!iso) {
printf("--\n");
igraph_write_graph_edgelist(&graph, stdout);
printf("--\n");
igraph_write_graph_edgelist(&othergraph, stdout);
igraph_destroy(&graph);
igraph_destroy(&othergraph);
return 50;
}
igraph_destroy(&graph);
igraph_destroy(&othergraph);
return 0;
}
