VALUE cIGraph_community_leading_eigenvector_naive(VALUE self, VALUE steps){
igraph_t *graph;
igraph_vector_t membership;
igraph_matrix_t *merges = malloc(sizeof(igraph_matrix_t));
igraph_arpack_options_t arpack_opt;
igraph_arpack_options_init(&arpack_opt);
int i,groupid,max_groupid;
VALUE groups, group, res;
Data_Get_Struct(self, igraph_t, graph);
igraph_matrix_init(merges,0,0);
igraph_vector_init(&membership,0);
igraph_community_leading_eigenvector_naive(graph,merges,&membership,
NUM2INT(steps), &arpack_opt);
max_groupid = 0;
for(i=0;i<igraph_vector_size(&membership);i++){
if(VECTOR(membership)[i] > max_groupid)
max_groupid = VECTOR(membership)[i];
}
groups = rb_ary_new();
for(i=0;i<max_groupid+1;i++){
rb_ary_push(groups,rb_ary_new());
}
for(i=0;i<igraph_vector_size(&membership);i++){
groupid = VECTOR(membership)[i];
if(groupid == -1)
groupid = 0;
group = RARRAY_PTR(groups)[groupid];
rb_ary_push(group,cIGraph_get_vertex_object(self, i));
}
res = rb_ary_new3(2,groups,
Data_Wrap_Struct(cIGraphMatrix, 0,
cIGraph_matrix_free, merges));
igraph_vector_destroy(&membership);
return res;
}
int main() {
igraph_t g;
igraph_matrix_t merges;
igraph_vector_t membership;
long int i, j;
igraph_bool_t split;
igraph_vector_t x;
igraph_real_t val;
igraph_arpack_options_t options;
/* Zachary Karate club */
igraph_small(&g, 0, IGRAPH_UNDIRECTED,
0, 1, 0, 2, 0, 3, 0, 4, 0, 5,
0, 6, 0, 7, 0, 8, 0, 10, 0, 11,
0, 12, 0, 13, 0, 17, 0, 19, 0, 21,
0, 31, 1, 2, 1, 3, 1, 7, 1, 13,
1, 17, 1, 19, 1, 21, 1, 30, 2, 3,
2, 7, 2, 8, 2, 9, 2, 13, 2, 27,
2, 28, 2, 32, 3, 7, 3, 12, 3, 13,
4, 6, 4, 10, 5, 6, 5, 10, 5, 16,
6, 16, 8, 30, 8, 32, 8, 33, 9, 33,
13, 33, 14, 32, 14, 33, 15, 32, 15, 33,
18, 32, 18, 33, 19, 33, 20, 32, 20, 33,
22, 32, 22, 33, 23, 25, 23, 27, 23, 29,
23, 32, 23, 33, 24, 25, 24, 27, 24, 31,
25, 31, 26, 29, 26, 33, 27, 33, 28, 31,
28, 33, 29, 32, 29, 33, 30, 32, 30, 33,
31, 32, 31, 33, 32, 33,
-1);
/* Make one step with all methods */
igraph_matrix_init(&merges, 0, 0);
igraph_vector_init(&membership, 0);
igraph_vector_init(&x, 0);
igraph_arpack_options_init(&options);
igraph_community_leading_eigenvector_naive(&g, &merges, &membership, 1, &options);
print_matrix(&merges);
print_vector(&membership);
igraph_community_leading_eigenvector(&g, &merges, &membership, 1, &options);
print_matrix(&merges);
print_vector(&membership);
igraph_vector_null(&membership);
igraph_community_leading_eigenvector_step(&g, &membership, 0, &split,
&x, &val, &options, 0);
print_vector(&membership);
print_vector(&x);
printf("\n");
/* Make all the steps */
igraph_community_leading_eigenvector(&g, &merges, &membership, igraph_vcount(&g),
&options);
print_matrix(&merges);
print_vector(&membership);
/* Try to make one more step from here, should fail */
for (i=0; i<igraph_matrix_nrow(&merges)+1; i++) {
igraph_community_leading_eigenvector_step(&g, &membership,
i, &split, &x, &val, &options, 0);
if (split) {
printf("Impossible, community %li splitted.\n", i);
return 1;
}
}
igraph_vector_destroy(&x);
igraph_vector_destroy(&membership);
igraph_matrix_destroy(&merges);
igraph_destroy(&g);
return 0;
}
