int main() { igraph_t g, tree; igraph_vector_t eb, edges; long int i; 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); igraph_vector_init(&eb, igraph_ecount(&g)); igraph_edge_betweenness(&g, &eb, IGRAPH_UNDIRECTED, /*weights=*/ 0); for (i=0; i<igraph_vector_size(&eb); i++) { VECTOR(eb)[i] = -VECTOR(eb)[i]; } igraph_minimum_spanning_tree_prim(&g, &tree, &eb); igraph_write_graph_edgelist(&tree, stdout); igraph_vector_init(&edges, 0); igraph_minimum_spanning_tree(&g, &edges, &eb); igraph_vector_print(&edges); igraph_vector_destroy(&edges); igraph_destroy(&tree); igraph_destroy(&g); igraph_vector_destroy(&eb); return 0; }
static void fit_rvine_trees(igraph_t **trees, const gsl_matrix *data, const dml_vine_weight_t weight, const dml_vine_trunc_t trunc, const dml_copula_indeptest_t indeptest, const double indeptest_level, const dml_copula_type_t *types, const size_t types_size, const dml_copula_select_t select, const gsl_rng *rng) { size_t m, n; igraph_t *graph; igraph_vector_t *graph_weight; dml_copula_t *copula; gsl_vector *x; igraph_integer_t e; // Edge id. igraph_integer_t a, aa, ab, b, ba, bb; // Vertex id. gsl_vector *u = NULL, *v = NULL; igraph_integer_t Cea, Ceb; gsl_vector_short *Ue, *Ua, *Ub; size_t k; dml_measure_t *measure; double tree_aic, copula_aic; gsl_permutation *perm, *rank, *u_rank = NULL, *v_rank = NULL; igraph_i_set_attribute_table(&igraph_cattribute_table); m = data->size1; n = data->size2; graph = g_malloc(sizeof(igraph_t)); graph_weight = g_malloc(sizeof(igraph_vector_t)); perm = gsl_permutation_alloc(m); for (k = 0; k < n - 1; k++) { // Tree index. if (k == 0) { igraph_full(graph, n, IGRAPH_UNDIRECTED, IGRAPH_NO_LOOPS); // Assign the observations to the nodes. for (size_t i = 0; i < n; i++) { // Variable and node index. x = gsl_vector_alloc(m); gsl_matrix_get_col(x, data, i); // Results of the h-function of the copula assigned to the // edge that corresponds to this vertex in the previous tree. // h for the h-function with its arguments in order and // hrev for the h-function with its arguments reversed. In the // first tree both are equal to the observations of the // corresponding variable, in the rest of the trees they differ. SETVAP(graph, "h", i, x); SETVAP(graph, "hrev", i, x); gsl_sort_vector_index(perm, x); rank = gsl_permutation_alloc(m); gsl_permutation_inverse(rank, perm); // Ranks of the h and hrev vectors. SETVAP(graph, "hrank", i, rank); SETVAP(graph, "hrevrank", i, rank); } for (e = 0; e < igraph_ecount(graph); e++) { igraph_edge(graph, e, &a, &b); // Variables "connected" by this edge. Ue = gsl_vector_short_calloc(n); gsl_vector_short_set(Ue, a, 1); gsl_vector_short_set(Ue, b, 1); SETEAP(graph, "Ue", e, Ue); // Conditioned set. SETEAN(graph, "Cea", e, a + 1); SETEAN(graph, "Ceb", e, b + 1); Cea = EAN(graph, "Cea", e); Ceb = EAN(graph, "Ceb", e); // Calculate the weight of the edge. u = VAP(graph, "h", a); v = VAP(graph, "h", b); u_rank = VAP(graph, "hrank", a); v_rank = VAP(graph, "hrank", b); // The conditioned set is ordered to make the order of the // arguments in the bivariate copulas unique as suggested in // Czado, C. (2010) Pair-Copula Constructions of Multivariate // Copulas. In Jaworski, P. and Durante, F. and Hardle, W. K. // and Rychlik, T. (eds.) Copula Theory and Its Applications, // Springer-Verlag, 93-109. if (Cea < Ceb) { rvine_set_weight(graph, weight, e, u, v, u_rank, v_rank); } else { rvine_set_weight(graph, weight, e, v, u, v_rank, u_rank); } } } else { igraph_empty(graph, n - k, IGRAPH_UNDIRECTED); // Adding all "possible" edges. for (a = 0; a < igraph_vcount(graph) - 1; a++) { for (b = a + 1; b < igraph_vcount(graph); b++) { igraph_edge(trees[k - 1], a, &aa, &ab); igraph_edge(trees[k - 1], b, &ba, &bb); // Checking the proximity condition. if (aa == ba || aa == bb || ab == ba || ab == bb) { igraph_add_edge(graph, a, b); igraph_get_eid(graph, &e, a, b, IGRAPH_UNDIRECTED, 1); // Variables "connected" by this edge and conditioned set. Ua = EAP(trees[k - 1], "Ue", a); Ub = EAP(trees[k - 1], "Ue", b); Ue = gsl_vector_short_calloc(n); for (size_t i = 0; i < n; i++) { gsl_vector_short_set(Ue, i, gsl_vector_short_get(Ua, i) | gsl_vector_short_get(Ub, i)); if (gsl_vector_short_get(Ua, i) && !gsl_vector_short_get(Ub, i)) { SETEAN(graph, "Cea", e, i + 1); } if (gsl_vector_short_get(Ub, i) && !gsl_vector_short_get(Ua, i)) { SETEAN(graph, "Ceb", e, i + 1); } } SETEAP(graph, "Ue", e, Ue); } } } // Compute pseudo-observations and edge weights. for (a = 0; a < igraph_vcount(graph); a++) { // See the comment in the code for the first tree. SETVAP(graph, "h", a, NULL); SETVAP(graph, "hrev", a, NULL); SETVAP(graph, "hrank", a, NULL); SETVAP(graph, "hrevrank", a, NULL); } for (e = 0; e < igraph_ecount(graph); e++) { igraph_edge(graph, e, &a, &b); Cea = EAN(graph, "Cea", e); Ceb = EAN(graph, "Ceb", e); // Assign u and u_rank. if ((Cea == EAN(trees[k - 1], "Cea", a) && (EAN(trees[k - 1], "Cea", a) < EAN(trees[k - 1], "Ceb", a))) || (Cea != EAN(trees[k - 1], "Cea", a) && (EAN(trees[k - 1], "Cea", a) > EAN(trees[k - 1], "Ceb", a)))) { u = VAP(graph, "h", a); if (u == NULL) { copula = EAP(trees[k - 1], "copula", a); measure = EAP(trees[k - 1], "measure", a); u = gsl_vector_alloc(m); dml_copula_h(copula, measure->x, measure->y, u); SETVAP(graph, "h", a, u); gsl_sort_vector_index(perm, u); rank = gsl_permutation_alloc(m); gsl_permutation_inverse(rank, perm); SETVAP(graph, "hrank", a, rank); } u_rank = VAP(graph, "hrank", a); } if ((Cea == EAN(trees[k - 1], "Cea", a) && (EAN(trees[k - 1], "Cea", a) > EAN(trees[k - 1], "Ceb", a))) || (Cea != EAN(trees[k - 1], "Cea", a) && (EAN(trees[k - 1], "Cea", a) < EAN(trees[k - 1], "Ceb", a)))) { u = VAP(graph, "hrev", a); if (u == NULL) { copula = EAP(trees[k - 1], "copula", a); measure = EAP(trees[k - 1], "measure", a); u = gsl_vector_alloc(m); dml_copula_h(copula, measure->y, measure->x, u); SETVAP(graph, "hrev", a, u); gsl_sort_vector_index(perm, u); rank = gsl_permutation_alloc(m); gsl_permutation_inverse(rank, perm); SETVAP(graph, "hrevrank", a, rank); } u_rank = VAP(graph, "hrevrank", a); } // Assign v and v_rank. if ((Ceb == EAN(trees[k - 1], "Cea", b) && (EAN(trees[k - 1], "Cea", b) < EAN(trees[k - 1], "Ceb", b))) || (Ceb != EAN(trees[k - 1], "Cea", b) && (EAN(trees[k - 1], "Cea", b) > EAN(trees[k - 1], "Ceb", b)))) { v = VAP(graph, "h", b); if (v == NULL) { copula = EAP(trees[k - 1], "copula", b); measure = EAP(trees[k - 1], "measure", b); v = gsl_vector_alloc(m); dml_copula_h(copula, measure->x, measure->y, v); SETVAP(graph, "h", b, v); gsl_sort_vector_index(perm, v); rank = gsl_permutation_alloc(m); gsl_permutation_inverse(rank, perm); SETVAP(graph, "hrank", b, rank); } v_rank = VAP(graph, "hrank", b); } if ((Ceb == EAN(trees[k - 1], "Cea", b) && (EAN(trees[k - 1], "Cea", b) > EAN(trees[k - 1], "Ceb", b))) || (Ceb != EAN(trees[k - 1], "Cea", b) && (EAN(trees[k - 1], "Cea", b) < EAN(trees[k - 1], "Ceb", b)))) { v = VAP(graph, "hrev", b); if (v == NULL) { copula = EAP(trees[k - 1], "copula", b); measure = EAP(trees[k - 1], "measure", b); v = gsl_vector_alloc(m); dml_copula_h(copula, measure->y, measure->x, v); SETVAP(graph, "hrev", b, v); gsl_sort_vector_index(perm, v); rank = gsl_permutation_alloc(m); gsl_permutation_inverse(rank, perm); SETVAP(graph, "hrevrank", b, rank); } v_rank = VAP(graph, "hrevrank", b); } // Set the weight of the edge. The arguments are ordered here. // The order determines the x and y fields of measure. if (Cea < Ceb) { rvine_set_weight(graph, weight, e, u, v, u_rank, v_rank); } else { rvine_set_weight(graph, weight, e, v, u, v_rank, u_rank); } } } // Compute the minimum weight spanning tree. trees[k] = g_malloc(sizeof(igraph_t)); igraph_vector_init(graph_weight, igraph_ecount(graph)); EANV(graph, "weight", graph_weight); igraph_minimum_spanning_tree_prim(graph, trees[k], graph_weight); igraph_vector_destroy(graph_weight); tree_aic = 0; for (e = 0; e < igraph_ecount(trees[k]); e++) { igraph_edge(trees[k], e, &a, &b); Cea = EAN(trees[k], "Cea", e); Ceb = EAN(trees[k], "Ceb", e); measure = EAP(trees[k], "measure", e); // Assign a bivariate copula to the edge. if (Cea < Ceb) { copula = dml_copula_select(measure->x, measure->y, measure, indeptest, indeptest_level, types, types_size, select, rng); // Get information for the truncation of the vine. if (trunc == DML_VINE_TRUNC_AIC) { dml_copula_aic(copula, measure->x, measure->y, &copula_aic); tree_aic += copula_aic; } } else { copula = dml_copula_select(measure->y, measure->x, measure, indeptest, indeptest_level, types, types_size, select, rng); // Get information for the truncation of the vine. if (trunc == DML_VINE_TRUNC_AIC) { dml_copula_aic(copula, measure->y, measure->x, &copula_aic); tree_aic += copula_aic; } } SETEAP(trees[k], "copula", e, copula); } igraph_destroy(graph); // Check if the vine should be truncated. if (trunc == DML_VINE_TRUNC_AIC && tree_aic >= 0) { // Free the memory used for the last tree. rvine_tree_cleanup(trees[k]); for (e = 0; e < igraph_ecount(trees[k]); e++) { copula = EAP(trees[k], "copula", e); dml_copula_free(copula); } igraph_destroy(trees[k]); g_free(trees[k]); trees[k] = NULL; break; } if (k > 0) rvine_tree_cleanup(trees[k - 1]); } // Cleanup the last tree if the vine was completely estimated. // If the vine was truncated, the last tree will be freed in // the function vine_fit_rvine, because the rvine_trees_to_vine // function needs some attributes of its edges. if (k == n - 1) { rvine_tree_cleanup(trees[n - 2]); } g_free(graph_weight); g_free(graph); gsl_permutation_free(perm); }