std::vector<double> Graph::betweenness() const {
igraph_vector_t results;
igraph_vs_t allnods;
std::vector<double> bet;
igraph_vector_init(&results, size);
igraph_vector_null(&results);
igraph_vs_all(&allnods);
igraph_betweenness(graph, &results, allnods, false);
bet.insert(bet.begin(), VECTOR(results), VECTOR(results) + size);
igraph_vector_destroy(&results);
igraph_vs_destroy(&allnods);
return bet;
}
/* call-seq:
* graph.betweenness(vs,mode) -> Array
*
* Returns an Array of betweenness centrality measures for the vertices given
* in the vs Array. mode defines whether directed paths or considered for
* directed graphs.
*/
VALUE cIGraph_betweenness(VALUE self, VALUE vs, VALUE directed){
igraph_t *graph;
igraph_vs_t vids;
igraph_vector_t vidv;
igraph_bool_t dir = 0;
igraph_vector_t res;
int i;
VALUE betweenness = rb_ary_new();
if(directed == Qtrue)
dir = 1;
//vector to hold the results of the degree calculations
IGRAPH_FINALLY(igraph_vector_destroy, &res);
IGRAPH_FINALLY(igraph_vector_destroy, &vidv);
IGRAPH_FINALLY(igraph_vs_destroy,&vids);
IGRAPH_CHECK(igraph_vector_init(&res,0));
Data_Get_Struct(self, igraph_t, graph);
//Convert an array of vertices to a vector of vertex ids
IGRAPH_CHECK(igraph_vector_init_int(&vidv,0));
cIGraph_vertex_arr_to_id_vec(self,vs,&vidv);
//create vertex selector from the vecotr of ids
IGRAPH_CHECK(igraph_vs_vector(&vids,&vidv));
IGRAPH_CHECK(igraph_betweenness(graph,&res,vids,dir));
for(i=0;i<igraph_vector_size(&res);i++){
rb_ary_push(betweenness,rb_float_new((float)VECTOR(res)[i]));
}
igraph_vector_destroy(&vidv);
igraph_vector_destroy(&res);
igraph_vs_destroy(&vids);
IGRAPH_FINALLY_CLEAN(3);
return betweenness;
}
int main() {
igraph_t g;
igraph_vector_t bet, bet2, weights, edges;
igraph_vector_t bbet, bbet2;
igraph_real_t nontriv[] = { 0, 19, 0, 16, 0, 20, 1, 19, 2, 5, 3, 7, 3, 8,
4, 15, 4, 11, 5, 8, 5, 19, 6, 7, 6, 10, 6, 8,
6, 9, 7, 20, 9, 10, 9, 20, 10, 19,
11, 12, 11, 20, 12, 15, 13, 15,
14, 18, 14, 16, 14, 17, 15, 16, 17, 18 };
igraph_real_t nontriv_weights[] = { 0.5249, 1, 0.1934, 0.6274, 0.5249,
0.0029, 0.3831, 0.05, 0.6274, 0.3831,
0.5249, 0.0587, 0.0579, 0.0562, 0.0562,
0.1934, 0.6274, 0.6274, 0.6274, 0.0418,
0.6274, 0.3511, 0.3511, 0.1486, 1, 1,
0.0711, 0.2409 };
igraph_real_t nontriv_res[] = { 20, 0, 0, 0, 0, 19, 80, 85, 32, 0, 10,
75, 70, 0, 36, 81, 60, 0, 19, 19, 86 };
/*******************************************************/
igraph_barabasi_game(/* graph= */ &g,
/* n= */ 1000,
/* power= */ 1,
/* m= */ 3,
/* outseq= */ 0,
/* outpref= */ 0,
/* A= */ 1,
/* directed= */ 0,
/* algo= */ IGRAPH_BARABASI_BAG,
/* start_from= */ 0);
igraph_simplify(&g, /* multiple= */ 1, /* loops= */ 1, /*edge_comb=*/ 0);
igraph_vector_init(&bet, 0);
igraph_vector_init(&bbet, 0);
igraph_betweenness_estimate(/* graph= */ &g,
/* res= */ &bet,
/* vids= */ igraph_vss_all(),
/* directed = */ 0,
/* cutoff= */ 2,
/* weights= */ 0,
/* nobigint= */ 1);
igraph_betweenness_estimate(/* graph= */ &g,
/* res= */ &bbet,
/* vids= */ igraph_vss_all(),
/* directed = */ 0,
/* cutoff= */ 2,
/* weights= */ 0,
/* nobigint= */ 0);
check(&bet, &bbet, 10);
igraph_vector_destroy(&bet);
igraph_vector_destroy(&bbet);
igraph_destroy(&g);
/*******************************************************/
igraph_tree(&g, 20000, 10, IGRAPH_TREE_UNDIRECTED);
igraph_vector_init(&bet, 0);
igraph_vector_init(&bbet, 0);
igraph_betweenness_estimate(/* graph= */ &g,
/* res= */ &bet,
/* vids= */ igraph_vss_all(),
/* directed = */ 0,
/* cutoff= */ 3,
/* weights= */ 0,
/* nobigint= */ 1);
igraph_betweenness_estimate(/* graph= */ &g,
/* res= */ &bbet,
/* vids= */ igraph_vss_all(),
/* directed = */ 0,
/* cutoff= */ 3,
/* weights= */ 0,
/* nobigint= */ 0);
check(&bet, &bbet, 20);
igraph_vector_init(&bet2, 0);
igraph_vector_init(&bbet2, 0);
igraph_vector_init(&weights, igraph_ecount(&g));
igraph_vector_fill(&weights, 1.0);
igraph_betweenness_estimate(/* graph= */ &g,
/* res= */ &bet2,
/* vids= */ igraph_vss_all(),
/* directed = */ 0,
/* cutoff= */ 3,
/* weights= */ &weights,
/* nobigint= */ 1);
igraph_betweenness_estimate(/* graph= */ &g,
/* res= */ &bbet2,
/* vids= */ igraph_vss_all(),
/* directed = */ 0,
/* cutoff= */ 3,
/* weights= */ &weights,
/* nobigint= */ 0);
if (!igraph_vector_all_e(&bet, &bet2)) {
return 1;
}
/* if (!igraph_vector_all_e(&bbet, &bbet2)) { */
/* return 2; */
/* } */
check(&bet, &bbet, 30);
check(&bet2, &bbet2, 40);
igraph_vector_destroy(&bet);
igraph_vector_destroy(&bet2);
igraph_vector_destroy(&bbet);
igraph_vector_destroy(&bbet2);
igraph_vector_destroy(&weights);
igraph_destroy(&g);
/* Non-trivial weighted graph */
igraph_vector_view(&edges, nontriv, sizeof(nontriv)/sizeof(igraph_real_t));
igraph_create(&g, &edges, 0, /* directed= */ 0);
igraph_vector_view(&weights, nontriv_weights,
sizeof(nontriv_weights)/sizeof(igraph_real_t));
igraph_vector_init(&bet, 0);
igraph_vector_init(&bbet, 0);
igraph_betweenness(/*graph=*/ &g, /*res=*/ &bet, /*vids=*/ igraph_vss_all(),
/*directed=*/0, /*weights=*/ &weights, /*nobigint=*/ 1);
igraph_betweenness(/*graph=*/ &g, /*res=*/ &bbet, /*vids=*/ igraph_vss_all(),
/*directed=*/0, /*weights=*/ &weights, /*nobigint=*/ 0);
igraph_vector_view(&bet2, nontriv_res,
sizeof(nontriv_res)/sizeof(igraph_real_t));
if (!igraph_vector_all_e(&bet, &bet2)) {
return 2;
}
check(&bet, &bbet, 50);
igraph_vector_destroy(&bet);
igraph_vector_destroy(&bbet);
igraph_destroy(&g);
if (IGRAPH_FINALLY_STACK_SIZE() != 0) return 3;
return 0;
}