/* call-seq:
* graph.bibcoupling(varray) -> Array
*
* Bibliographic coupling.
*
* The bibliographic coupling of two vertices is the number of other
* vertices they both cite. The
* bibliographic coupling score for each given vertex and all other
* vertices in the graph will be calculated.
*
*/
VALUE cIGraph_bibcoupling(VALUE self, VALUE vs){
igraph_t *graph;
igraph_vs_t vids;
igraph_vector_t vidv;
igraph_matrix_t res;
int i;
int j;
VALUE row;
VALUE path_length;
VALUE matrix = rb_ary_new();
int n_row;
int n_col;
Data_Get_Struct(self, igraph_t, graph);
n_row = NUM2INT(rb_funcall(vs,rb_intern("length"),0));
n_col = igraph_vcount(graph);
//matrix to hold the results of the calculations
igraph_matrix_init(&res,n_row,n_col);
//Convert an array of vertices to a vector of vertex ids
igraph_vector_init_int(&vidv,0);
cIGraph_vertex_arr_to_id_vec(self,vs,&vidv);
//create vertex selector from the vecotr of ids
igraph_vs_vector(&vids,&vidv);
igraph_bibcoupling(graph,&res,vids);
for(i=0; i<igraph_matrix_nrow(&res); i++){
row = rb_ary_new();
rb_ary_push(matrix,row);
for(j=0; j<igraph_matrix_ncol(&res); j++){
path_length = INT2NUM(MATRIX(res,i,j));
rb_ary_push(row,path_length);
}
}
igraph_vector_destroy(&vidv);
igraph_matrix_destroy(&res);
igraph_vs_destroy(&vids);
return matrix;
}
int main() {
igraph_t g;
igraph_matrix_t m;
igraph_small(&g, 0, IGRAPH_DIRECTED,
0,1, 2,1, 2,0, 3,0,
-1);
igraph_matrix_init(&m, 0, 0);
igraph_bibcoupling(&g, &m, igraph_vss_all());
print_matrix(&m, stdout);
igraph_cocitation(&g, &m, igraph_vss_all());
print_matrix(&m, stdout);
igraph_matrix_destroy(&m);
igraph_destroy(&g);
return 0;
}
