int main() {
igraph_t g;
igraph_vector_t edges;
igraph_vector_t vids;
igraph_integer_t class;
igraph_vector_init_int_end(&edges, -1,
0,1, 1,3, 1,4, 1,6, 3,1,
4,1, 4,2, 6,4, 6,5, 7,8,
8,7, 7,9, 9,7, 8,9, 9,8,
-1);
igraph_create(&g, &edges, 0, IGRAPH_DIRECTED);
igraph_vector_destroy(&edges);
igraph_vector_init_int_end(&vids, -1, 1,4,6, -1);
igraph_isoclass_subgraph(&g, &vids, &class);
printf("class: %i\n", (int)class);
igraph_vector_destroy(&vids);
igraph_vector_init_int_end(&vids, -1, 0,1,3, -1);
igraph_isoclass_subgraph(&g, &vids, &class);
printf("class: %i\n", (int)class);
igraph_vector_destroy(&vids);
igraph_vector_init_int_end(&vids, -1, 7,8,9, -1);
igraph_isoclass_subgraph(&g, &vids, &class);
printf("class: %i\n", (int)class);
igraph_vector_destroy(&vids);
igraph_vector_init_int_end(&vids, -1, 0,2,5, -1);
igraph_isoclass_subgraph(&g, &vids, &class);
printf("class: %i\n", (int)class);
igraph_vector_destroy(&vids);
igraph_destroy(&g);
return 0;
}
int main() {
igraph_t g;
igraph_vector_t weights, result;
igraph_bool_t dag;
int retval;
igraph_vector_init(&result, 0);
igraph_set_error_handler(&igraph_error_handler_printignore);
/***********************************************************************/
/* Exact solution with integer programming */
/***********************************************************************/
/* Simple unweighted graph */
igraph_small(&g, 0, IGRAPH_DIRECTED, 0,1, 1,2, 2,0, 2,3, 2,4, 0,4, 4,3, 5,0, 6,5, -1);
retval = igraph_feedback_arc_set(&g, &result, 0, IGRAPH_FAS_EXACT_IP);
if (retval == IGRAPH_UNIMPLEMENTED)
return 77;
igraph_vector_print(&result);
igraph_delete_edges(&g, igraph_ess_vector(&result));
igraph_is_dag(&g, &dag);
if (!dag)
return 1;
igraph_destroy(&g);
/* Simple weighted graph */
igraph_small(&g, 0, IGRAPH_DIRECTED, 0,1, 1,2, 2,0, 2,3, 2,4, 0,4, 4,3, 5,0, 6,5, -1);
igraph_vector_init_int_end(&weights, -1, 1, 1, 3, 1, 1, 1, 1, 1, 1, -1);
igraph_feedback_arc_set(&g, &result, &weights, IGRAPH_FAS_EXACT_IP);
igraph_vector_print(&result);
igraph_delete_edges(&g, igraph_ess_vector(&result));
igraph_is_dag(&g, &dag);
if (!dag)
return 2;
igraph_vector_destroy(&weights);
igraph_destroy(&g);
/* Simple unweighted graph with loops */
igraph_small(&g, 0, IGRAPH_DIRECTED, 0,1, 1,2, 2,0, 2,3, 2,4, 0,4, 4,3, 5,0, 6,5, 1,1, 4,4, -1);
igraph_feedback_arc_set(&g, &result, 0, IGRAPH_FAS_EXACT_IP);
igraph_vector_print(&result);
igraph_delete_edges(&g, igraph_ess_vector(&result));
igraph_is_dag(&g, &dag);
if (!dag)
return 3;
igraph_destroy(&g);
/* Disjoint union of two almost identical graphs */
igraph_small(&g, 0, IGRAPH_DIRECTED,
0,1, 1,2, 2,0, 2,3, 2,4, 0,4, 4,3, 5,0, 6,5, 1,1, 4,4,
7,8, 8,9, 9,7, 9,10, 9,11, 7,11, 11,10, 12,7, 13,12,
-1);
igraph_feedback_arc_set(&g, &result, 0, IGRAPH_FAS_EXACT_IP);
igraph_vector_print(&result);
igraph_delete_edges(&g, igraph_ess_vector(&result));
igraph_is_dag(&g, &dag);
if (!dag)
return 4;
igraph_destroy(&g);
/* Graph with lots of isolated vertices */
igraph_small(&g, 10000, IGRAPH_DIRECTED, 0,1, -1);
igraph_feedback_arc_set(&g, &result, 0, IGRAPH_FAS_EXACT_IP);
igraph_vector_print(&result);
igraph_delete_edges(&g, igraph_ess_vector(&result));
igraph_is_dag(&g, &dag);
if (!dag)
return 5;
igraph_destroy(&g);
igraph_vector_destroy(&result);
return 0;
}
int main() {
igraph_t g, extd_g;
igraph_matrix_t coords;
igraph_vector_t edgelist, extd_edgelist, extd_to_orig_eids;
igraph_vector_t layers;
igraph_matrix_init(&coords, 0, 0);
igraph_vector_init(&extd_to_orig_eids, 0);
/* Layout on simple graph with predefined layers */
igraph_vector_init_int_end(&layers, -1, 0,1,1,2,3,3,4,4,5, -1);
igraph_vector_init_int_end(&edgelist, -1,
0,1, 0,2, 0,3, 1,2, 2,2, 1,4, 2,5, 4,6, 5,7, 6,8, 7,8,
3,8, 8,1, 8,2, -1);
igraph_create(&g, &edgelist, 0, 1);
igraph_layout_sugiyama(&g, &coords, 0, 0, &layers,
/* hgap = */ 1,
/* vgap = */ 1,
/* maxiter = */ 100,
/* weights = */ 0);
igraph_matrix_print(&coords);
printf("===\n");
/* Same, but this time also return the extended graph */
igraph_layout_sugiyama(&g, &coords, &extd_g, &extd_to_orig_eids, &layers,
/* hgap = */ 1,
/* vgap = */ 1,
/* maxiter = */ 100,
/* weights = */ 0);
igraph_matrix_print(&coords);
printf("===\n");
igraph_vector_init(&extd_edgelist, 0);
igraph_get_edgelist(&extd_g, &extd_edgelist, 0);
igraph_vector_print(&extd_edgelist);
igraph_vector_destroy(&extd_edgelist);
igraph_destroy(&extd_g);
printf("===\n");
igraph_vector_print(&extd_to_orig_eids);
printf("===\n");
igraph_vector_destroy(&layers);
/* Same, but with automatic layering */
igraph_layout_sugiyama(&g, &coords, 0, 0, 0,
/* hgap = */ 1,
/* vgap = */ 1,
/* maxiter = */ 100,
/* weights = */ 0);
igraph_matrix_print(&coords);
printf("===\n");
/* Layering with gaps in it */
igraph_vector_init_int_end(&layers, -1, 0,2,2,4,6,6,12,12,15, -1);
igraph_layout_sugiyama(&g, &coords, 0, 0, &layers,
/* hgap = */ 1,
/* vgap = */ 1,
/* maxiter = */ 100,
/* weights = */ 0);
igraph_matrix_print(&coords);
igraph_vector_destroy(&layers);
printf("===\n");
igraph_vector_destroy(&edgelist);
igraph_matrix_destroy(&coords);
igraph_vector_destroy(&extd_to_orig_eids);
igraph_destroy(&g);
return 0;
}
