static int igraph_i_bridges_rec(const igraph_t *graph, const igraph_inclist_t *il, igraph_integer_t u, igraph_integer_t *time, igraph_vector_t *bridges, igraph_vector_bool_t *visited, igraph_vector_int_t *disc, igraph_vector_int_t *low, igraph_vector_int_t *parent) {
igraph_vector_int_t *incedges;
long nc; /* neighbour count */
long i;
VECTOR(*visited)[u] = 1;
*time += 1;
VECTOR(*disc)[u] = *time;
VECTOR(*low)[u] = *time;
incedges = igraph_inclist_get(il, u);
nc = igraph_vector_int_size(incedges);
for (i=0; i < nc; ++i) {
long edge = (long) VECTOR(*incedges)[i];
igraph_integer_t v = IGRAPH_TO(graph, edge) == u ? IGRAPH_FROM(graph, edge) : IGRAPH_TO(graph, edge);
if (! VECTOR(*visited)[v]) {
VECTOR(*parent)[v] = u;
IGRAPH_CHECK(igraph_i_bridges_rec(graph, il, v, time, bridges, visited, disc, low, parent));
VECTOR(*low)[u] = VECTOR(*low)[u] < VECTOR(*low)[v] ? VECTOR(*low)[u] : VECTOR(*low)[v];
if (VECTOR(*low)[v] > VECTOR(*disc)[u])
IGRAPH_CHECK(igraph_vector_push_back(bridges, edge));
}
else if (v != VECTOR(*parent)[u]) {
VECTOR(*low)[u] = VECTOR(*low)[u] < VECTOR(*disc)[v] ? VECTOR(*low)[u] : VECTOR(*disc)[v];
}
}
return IGRAPH_SUCCESS;
}
int igraph_adjlist_init(const igraph_t *graph, igraph_adjlist_t *al,
igraph_neimode_t mode) {
long int i;
if (mode != IGRAPH_IN && mode != IGRAPH_OUT && mode != IGRAPH_ALL) {
IGRAPH_ERROR("Cannot create adjlist view", IGRAPH_EINVMODE);
}
if (!igraph_is_directed(graph)) { mode=IGRAPH_ALL; }
al->length=igraph_vcount(graph);
al->adjs=igraph_Calloc(al->length, igraph_vector_t);
if (al->adjs == 0) {
IGRAPH_ERROR("Cannot create adjlist view", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_adjlist_destroy, al);
for (i=0; i<al->length; i++) {
IGRAPH_ALLOW_INTERRUPTION();
IGRAPH_CHECK(igraph_vector_init(&al->adjs[i], 0));
IGRAPH_CHECK(igraph_neighbors(graph, &al->adjs[i], i, mode));
}
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
int igraph_i_largest_cliques_store(const igraph_vector_t* clique, void* data, igraph_bool_t* cont) {
igraph_vector_ptr_t* result = (igraph_vector_ptr_t*)data;
igraph_vector_t* vec;
long int i, n;
/* Is the current clique at least as large as the others that we have found? */
if (!igraph_vector_ptr_empty(result)) {
n = igraph_vector_size(clique);
if (n < igraph_vector_size(VECTOR(*result)[0]))
return IGRAPH_SUCCESS;
if (n > igraph_vector_size(VECTOR(*result)[0])) {
for (i = 0; i < igraph_vector_ptr_size(result); i++)
igraph_vector_destroy(VECTOR(*result)[i]);
igraph_vector_ptr_free_all(result);
igraph_vector_ptr_resize(result, 0);
}
}
vec = igraph_Calloc(1, igraph_vector_t);
if (vec == 0)
IGRAPH_ERROR("cannot allocate memory for storing next clique", IGRAPH_ENOMEM);
IGRAPH_CHECK(igraph_vector_copy(vec, clique));
IGRAPH_CHECK(igraph_vector_ptr_push_back(result, vec));
return IGRAPH_SUCCESS;
}
/**
* \ingroup interface
* \function igraph_empty_attrs
* \brief Creates an empty graph with some vertices, no edges and some graph attributes.
*
* </para><para>
* Use this instead of \ref igraph_empty() if you wish to add some graph
* attributes right after initialization. This function is currently
* not very interesting for the ordinary user, just supply 0 here or
* use \ref igraph_empty().
* \param graph Pointer to a not-yet initialized graph object.
* \param n The number of vertices in the graph, a non-negative
* integer number is expected.
* \param directed Whether the graph is directed or not.
* \param attr The attributes.
* \return Error code:
* \c IGRAPH_EINVAL: invalid number of vertices.
*
* Time complexity: O(|V|) for a graph with
* |V| vertices (and no edges).
*/
int igraph_empty_attrs(igraph_t *graph, igraph_integer_t n, igraph_bool_t directed, void* attr) {
if (n<0) {
IGRAPH_ERROR("cannot create empty graph with negative number of vertices",
IGRAPH_EINVAL);
}
if (!IGRAPH_FINITE(n)) {
IGRAPH_ERROR("number of vertices is not finite (NA, NaN or Inf)", IGRAPH_EINVAL);
}
graph->n=0;
graph->directed=directed;
IGRAPH_VECTOR_INIT_FINALLY(&graph->from, 0);
IGRAPH_VECTOR_INIT_FINALLY(&graph->to, 0);
IGRAPH_VECTOR_INIT_FINALLY(&graph->oi, 0);
IGRAPH_VECTOR_INIT_FINALLY(&graph->ii, 0);
IGRAPH_VECTOR_INIT_FINALLY(&graph->os, 1);
IGRAPH_VECTOR_INIT_FINALLY(&graph->is, 1);
VECTOR(graph->os)[0]=0;
VECTOR(graph->is)[0]=0;
/* init attributes */
graph->attr=0;
IGRAPH_CHECK(igraph_i_attribute_init(graph, attr));
/* add the vertices */
IGRAPH_CHECK(igraph_add_vertices(graph, n, 0));
IGRAPH_FINALLY_CLEAN(6);
return 0;
}
/**
* \ingroup interface
* \function igraph_add_vertices
* \brief Adds vertices to a graph.
*
* </para><para>
* This function invalidates all iterators.
*
* \param graph The graph object to extend.
* \param nv Non-negative integer giving the number of
* vertices to add.
* \param attr The attributes of the new vertices, only used by
* high level interfaces, you can supply 0 here.
* \return Error code:
* \c IGRAPH_EINVAL: invalid number of new
* vertices.
*
* Time complexity: O(|V|) where
* |V| is
* the number of vertices in the \em new, extended graph.
*/
int igraph_add_vertices(igraph_t *graph, igraph_integer_t nv, void *attr) {
long int ec=igraph_ecount(graph);
long int i;
if (nv < 0) {
IGRAPH_ERROR("cannot add negative number of vertices", IGRAPH_EINVAL);
}
IGRAPH_CHECK(igraph_vector_reserve(&graph->os, graph->n+nv+1));
IGRAPH_CHECK(igraph_vector_reserve(&graph->is, graph->n+nv+1));
igraph_vector_resize(&graph->os, graph->n+nv+1); /* reserved */
igraph_vector_resize(&graph->is, graph->n+nv+1); /* reserved */
for (i=graph->n+1; i<graph->n+nv+1; i++) {
VECTOR(graph->os)[i]=ec;
VECTOR(graph->is)[i]=ec;
}
graph->n += nv;
if (graph->attr) {
IGRAPH_CHECK(igraph_i_attribute_add_vertices(graph, nv, attr));
}
return 0;
}
int igraph_similarity_inverse_log_weighted(const igraph_t *graph,
igraph_matrix_t *res, const igraph_vs_t vids, igraph_neimode_t mode) {
igraph_vector_t weights;
igraph_neimode_t mode0;
long int i, no_of_nodes;
switch (mode) {
case IGRAPH_OUT: mode0 = IGRAPH_IN; break;
case IGRAPH_IN: mode0 = IGRAPH_OUT; break;
default: mode0 = IGRAPH_ALL;
}
no_of_nodes = igraph_vcount(graph);
IGRAPH_VECTOR_INIT_FINALLY(&weights, no_of_nodes);
IGRAPH_CHECK(igraph_degree(graph, &weights, igraph_vss_all(), mode0, 1));
for (i=0; i < no_of_nodes; i++) {
if (VECTOR(weights)[i] > 1)
VECTOR(weights)[i] = 1.0 / log(VECTOR(weights)[i]);
}
IGRAPH_CHECK(igraph_cocitation_real(graph, res, vids, mode0, &weights));
igraph_vector_destroy(&weights);
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
int igraph_i_eigen_matrix_lapack_common(const igraph_matrix_t *A,
const igraph_eigen_which_t *which,
igraph_vector_complex_t *values,
igraph_matrix_complex_t *vectors) {
igraph_vector_t valuesreal, valuesimag;
igraph_matrix_t vectorsright, *myvectors= vectors ? &vectorsright : 0;
int n=(int) igraph_matrix_nrow(A);
int info=1;
IGRAPH_VECTOR_INIT_FINALLY(&valuesreal, n);
IGRAPH_VECTOR_INIT_FINALLY(&valuesimag, n);
if (vectors) { IGRAPH_MATRIX_INIT_FINALLY(&vectorsright, n, n); }
IGRAPH_CHECK(igraph_lapack_dgeev(A, &valuesreal, &valuesimag,
/*vectorsleft=*/ 0, myvectors, &info));
IGRAPH_CHECK(igraph_i_eigen_matrix_lapack_reorder(&valuesreal,
&valuesimag,
myvectors, which, values,
vectors));
if (vectors) {
igraph_matrix_destroy(&vectorsright);
IGRAPH_FINALLY_CLEAN(1);
}
igraph_vector_destroy(&valuesimag);
igraph_vector_destroy(&valuesreal);
IGRAPH_FINALLY_CLEAN(2);
return 0;
}
int igraph_attribute_combination(igraph_attribute_combination_t *comb, ...) {
va_list ap;
IGRAPH_CHECK(igraph_attribute_combination_init(comb));
va_start(ap, comb);
while (1) {
void *func=0;
igraph_attribute_combination_type_t type;
const char *name;
name=va_arg(ap, const char *);
if (name == IGRAPH_NO_MORE_ATTRIBUTES) { break; }
type=(igraph_attribute_combination_type_t)va_arg(ap, int);
if (type == IGRAPH_ATTRIBUTE_COMBINE_FUNCTION) {
func=va_arg(ap, void*);
}
if (strlen(name)==0) { name=0; }
IGRAPH_CHECK(igraph_attribute_combination_add(comb, name, type, func));
}
/**
* \ingroup structural
* \function igraph_similarity_jaccard_es
* \brief Jaccard similarity coefficient for a given edge selector.
*
* </para><para>
* The Jaccard similarity coefficient of two vertices is the number of common
* neighbors divided by the number of vertices that are neighbors of at
* least one of the two vertices being considered. This function calculates
* the pairwise Jaccard similarities for the endpoints of edges in a given edge
* selector.
*
* \param graph The graph object to analyze
* \param res Pointer to a vector, the result of the calculation will
* be stored here. The number of elements is the same as the number
* of edges in \p es.
* \param es An edge selector that specifies the edges to be included in the
* result.
* \param mode The type of neighbors to be used for the calculation in
* directed graphs. Possible values:
* \clist
* \cli IGRAPH_OUT
* the outgoing edges will be considered for each node.
* \cli IGRAPH_IN
* the incoming edges will be considered for each node.
* \cli IGRAPH_ALL
* the directed graph is considered as an undirected one for the
* computation.
* \endclist
* \param loops Whether to include the vertices themselves in the neighbor
* sets.
* \return Error code:
* \clist
* \cli IGRAPH_ENOMEM
* not enough memory for temporary data.
* \cli IGRAPH_EINVVID
* invalid vertex id passed.
* \cli IGRAPH_EINVMODE
* invalid mode argument.
* \endclist
*
* Time complexity: O(nd), n is the number of edges in the edge selector, d is
* the (maximum) degree of the vertices in the graph.
*
* \sa \ref igraph_similarity_jaccard() and \ref igraph_similarity_jaccard_pairs()
* to calculate the Jaccard similarity between all pairs of a vertex set or
* some selected vertex pairs, or \ref igraph_similarity_dice(),
* \ref igraph_similarity_dice_pairs() and \ref igraph_similarity_dice_es() for a
* measure very similar to the Jaccard coefficient
*
* \example examples/simple/igraph_similarity.c
*/
int igraph_similarity_jaccard_es(const igraph_t *graph, igraph_vector_t *res,
const igraph_es_t es, igraph_neimode_t mode, igraph_bool_t loops) {
igraph_vector_t v;
igraph_eit_t eit;
IGRAPH_VECTOR_INIT_FINALLY(&v, 0);
IGRAPH_CHECK(igraph_eit_create(graph, es, &eit));
IGRAPH_FINALLY(igraph_eit_destroy, &eit);
while (!IGRAPH_EIT_END(eit)) {
long int eid = IGRAPH_EIT_GET(eit);
igraph_vector_push_back(&v, IGRAPH_FROM(graph, eid));
igraph_vector_push_back(&v, IGRAPH_TO(graph, eid));
IGRAPH_EIT_NEXT(eit);
}
igraph_eit_destroy(&eit);
IGRAPH_FINALLY_CLEAN(1);
IGRAPH_CHECK(igraph_similarity_jaccard_pairs(graph, res, &v, mode, loops));
igraph_vector_destroy(&v);
IGRAPH_FINALLY_CLEAN(1);
return IGRAPH_SUCCESS;
}
int igraph_inclist_init(const igraph_t *graph,
igraph_inclist_t *il,
igraph_neimode_t mode) {
long int i;
if (mode != IGRAPH_IN && mode != IGRAPH_OUT && mode != IGRAPH_ALL) {
IGRAPH_ERROR("Cannot create incidence list view", IGRAPH_EINVMODE);
}
if (!igraph_is_directed(graph)) { mode=IGRAPH_ALL; }
il->length=igraph_vcount(graph);
il->incs=igraph_Calloc(il->length, igraph_vector_t);
if (il->incs == 0) {
IGRAPH_ERROR("Cannot create incidence list view", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_inclist_destroy, il);
for (i=0; i<il->length; i++) {
IGRAPH_ALLOW_INTERRUPTION();
IGRAPH_CHECK(igraph_vector_init(&il->incs[i], 0));
IGRAPH_CHECK(igraph_incident(graph, &il->incs[i], i, mode));
}
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
int igraph_get_edgelist(const igraph_t *graph, igraph_vector_t *res, igraph_bool_t bycol) {
igraph_eit_t edgeit;
long int no_of_edges=igraph_ecount(graph);
long int vptr=0;
igraph_integer_t from, to;
IGRAPH_CHECK(igraph_vector_resize(res, no_of_edges*2));
IGRAPH_CHECK(igraph_eit_create(graph, igraph_ess_all(IGRAPH_EDGEORDER_ID),
&edgeit));
IGRAPH_FINALLY(igraph_eit_destroy, &edgeit);
if (bycol) {
while (!IGRAPH_EIT_END(edgeit)) {
igraph_edge(graph, IGRAPH_EIT_GET(edgeit), &from, &to);
VECTOR(*res)[vptr]=from;
VECTOR(*res)[vptr+no_of_edges]=to;
vptr++;
IGRAPH_EIT_NEXT(edgeit);
}
} else {
while (!IGRAPH_EIT_END(edgeit)) {
igraph_edge(graph, IGRAPH_EIT_GET(edgeit), &from, &to);
VECTOR(*res)[vptr++]=from;
VECTOR(*res)[vptr++]=to;
IGRAPH_EIT_NEXT(edgeit);
}
}
igraph_eit_destroy(&edgeit);
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
int igraph_is_separator(const igraph_t *graph,
const igraph_vs_t candidate,
igraph_bool_t *res) {
long int no_of_nodes=igraph_vcount(graph);
igraph_vector_bool_t removed;
igraph_dqueue_t Q;
igraph_vector_t neis;
igraph_vit_t vit;
IGRAPH_CHECK(igraph_vit_create(graph, candidate, &vit));
IGRAPH_FINALLY(igraph_vit_destroy, &vit);
IGRAPH_CHECK(igraph_vector_bool_init(&removed, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_bool_destroy, &removed);
IGRAPH_CHECK(igraph_dqueue_init(&Q, 100));
IGRAPH_FINALLY(igraph_dqueue_destroy, &Q);
IGRAPH_VECTOR_INIT_FINALLY(&neis, 0);
IGRAPH_CHECK(igraph_i_is_separator(graph, &vit, -1, res, &removed,
&Q, &neis, no_of_nodes));
igraph_vector_destroy(&neis);
igraph_dqueue_destroy(&Q);
igraph_vector_bool_destroy(&removed);
igraph_vit_destroy(&vit);
IGRAPH_FINALLY_CLEAN(4);
return 0;
}
int igraph_matrix_complex_imag(const igraph_matrix_complex_t *v,
igraph_matrix_t *imag) {
long int nrow=igraph_matrix_complex_nrow(v);
long int ncol=igraph_matrix_complex_ncol(v);
IGRAPH_CHECK(igraph_matrix_resize(imag, nrow, ncol));
IGRAPH_CHECK(igraph_vector_complex_imag(&v->data, &imag->data));
return 0;
}
int igraph_matrix_complex_real(const igraph_matrix_complex_t *v,
igraph_matrix_t *real) {
long int nrow=igraph_matrix_complex_nrow(v);
long int ncol=igraph_matrix_complex_ncol(v);
IGRAPH_CHECK(igraph_matrix_resize(real, nrow, ncol));
IGRAPH_CHECK(igraph_vector_complex_real(&v->data, &real->data));
return 0;
}
/* removes multiple edges and returns new edge id's for each edge in |E|log|E| */
int igraph_i_multilevel_simplify_multiple(igraph_t *graph, igraph_vector_t *eids) {
long int ecount = igraph_ecount(graph);
long int i, l = -1, last_from = -1, last_to = -1;
igraph_bool_t directed = igraph_is_directed(graph);
igraph_integer_t from, to;
igraph_vector_t edges;
igraph_i_multilevel_link *links;
/* Make sure there's enough space in eids to store the new edge IDs */
IGRAPH_CHECK(igraph_vector_resize(eids, ecount));
links = igraph_Calloc(ecount, igraph_i_multilevel_link);
if (links == 0) {
IGRAPH_ERROR("multi-level community structure detection failed", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(free, links);
for (i = 0; i < ecount; i++) {
igraph_edge(graph, (igraph_integer_t) i, &from, &to);
links[i].from = from;
links[i].to = to;
links[i].id = i;
}
qsort((void*)links, (size_t) ecount, sizeof(igraph_i_multilevel_link),
igraph_i_multilevel_link_cmp);
IGRAPH_VECTOR_INIT_FINALLY(&edges, 0);
for (i = 0; i < ecount; i++) {
if (links[i].from == last_from && links[i].to == last_to) {
VECTOR(*eids)[links[i].id] = l;
continue;
}
last_from = links[i].from;
last_to = links[i].to;
igraph_vector_push_back(&edges, last_from);
igraph_vector_push_back(&edges, last_to);
l++;
VECTOR(*eids)[links[i].id] = l;
}
free(links);
IGRAPH_FINALLY_CLEAN(1);
igraph_destroy(graph);
IGRAPH_CHECK(igraph_create(graph, &edges, igraph_vcount(graph), directed));
igraph_vector_destroy(&edges);
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
int igraph_i_maximum_bipartite_matching_unweighted_relabel(const igraph_t* graph,
const igraph_vector_bool_t* types, igraph_vector_t* labels,
igraph_vector_long_t* match, igraph_bool_t smaller_set) {
long int i, j, n, no_of_nodes = igraph_vcount(graph), matched_to;
igraph_dqueue_long_t q;
igraph_vector_t neis;
debug("Running global relabeling.\n");
/* Set all the labels to no_of_nodes first */
igraph_vector_fill(labels, no_of_nodes);
/* Allocate vector for neighbors */
IGRAPH_VECTOR_INIT_FINALLY(&neis, 0);
/* Create a FIFO for the BFS and initialize it with the unmatched rows
* (i.e. members of the larger set) */
IGRAPH_CHECK(igraph_dqueue_long_init(&q, 0));
IGRAPH_FINALLY(igraph_dqueue_long_destroy, &q);
for (i = 0; i < no_of_nodes; i++) {
if (VECTOR(*types)[i] != smaller_set && VECTOR(*match)[i] == -1) {
IGRAPH_CHECK(igraph_dqueue_long_push(&q, i));
VECTOR(*labels)[i] = 0;
}
}
/* Run the BFS */
while (!igraph_dqueue_long_empty(&q)) {
long int v = igraph_dqueue_long_pop(&q);
long int w;
IGRAPH_CHECK(igraph_neighbors(graph, &neis, (igraph_integer_t) v,
IGRAPH_ALL));
n = igraph_vector_size(&neis);
//igraph_vector_shuffle(&neis);
for (j = 0; j < n; j++) {
w = (long int) VECTOR(neis)[j];
if (VECTOR(*labels)[w] == no_of_nodes) {
VECTOR(*labels)[w] = VECTOR(*labels)[v] + 1;
matched_to = VECTOR(*match)[w];
if (matched_to != -1 && VECTOR(*labels)[matched_to] == no_of_nodes) {
IGRAPH_CHECK(igraph_dqueue_long_push(&q, matched_to));
VECTOR(*labels)[matched_to] = VECTOR(*labels)[w] + 1;
}
}
}
}
printf("Inside relabel : ");
igraph_vector_print(labels);
igraph_dqueue_long_destroy(&q);
igraph_vector_destroy(&neis);
IGRAPH_FINALLY_CLEAN(2);
return IGRAPH_SUCCESS;
}
int igraph_eigen_matrix_symmetric(const igraph_matrix_t *A,
const igraph_sparsemat_t *sA,
igraph_arpack_function_t *fun, int n,
void *extra,
igraph_eigen_algorithm_t algorithm,
const igraph_eigen_which_t *which,
igraph_arpack_options_t *options,
igraph_arpack_storage_t *storage,
igraph_vector_t *values,
igraph_matrix_t *vectors) {
IGRAPH_CHECK(igraph_i_eigen_checks(A, sA, fun, n));
if (which->pos != IGRAPH_EIGEN_LM &&
which->pos != IGRAPH_EIGEN_SM &&
which->pos != IGRAPH_EIGEN_LA &&
which->pos != IGRAPH_EIGEN_SA &&
which->pos != IGRAPH_EIGEN_BE &&
which->pos != IGRAPH_EIGEN_ALL &&
which->pos != IGRAPH_EIGEN_INTERVAL &&
which->pos != IGRAPH_EIGEN_SELECT) {
IGRAPH_ERROR("Invalid 'pos' position in 'which'", IGRAPH_EINVAL);
}
switch (algorithm) {
case IGRAPH_EIGEN_AUTO:
if (which->howmany==n || n < 100) {
IGRAPH_CHECK(igraph_i_eigen_matrix_symmetric_lapack(A, sA, fun, n,
extra, which,
values, vectors));
} else {
IGRAPH_CHECK(igraph_i_eigen_matrix_symmetric_arpack(A, sA, fun, n,
extra, which,
options, storage,
values, vectors));
}
break;
case IGRAPH_EIGEN_LAPACK:
IGRAPH_CHECK(igraph_i_eigen_matrix_symmetric_lapack(A, sA, fun, n ,extra,
which, values,
vectors));
break;
case IGRAPH_EIGEN_ARPACK:
IGRAPH_CHECK(igraph_i_eigen_matrix_symmetric_arpack(A, sA, fun, n, extra,
which, options,
storage,
values, vectors));
break;
default:
IGRAPH_ERROR("Unknown 'algorithm'", IGRAPH_EINVAL);
}
return 0;
}
int igraph_i_maximal_or_largest_cliques_or_indsets(const igraph_t *graph,
igraph_vector_ptr_t *res,
igraph_integer_t *clique_number,
igraph_bool_t keep_only_largest,
igraph_bool_t complementer) {
igraph_i_max_ind_vsets_data_t clqdata;
long int no_of_nodes = igraph_vcount(graph), i;
if (igraph_is_directed(graph))
IGRAPH_WARNING("directionality of edges is ignored for directed graphs");
clqdata.matrix_size=no_of_nodes;
clqdata.keep_only_largest=keep_only_largest;
if (complementer)
IGRAPH_CHECK(igraph_adjlist_init_complementer(graph, &clqdata.adj_list, IGRAPH_ALL, 0));
else
IGRAPH_CHECK(igraph_adjlist_init(graph, &clqdata.adj_list, IGRAPH_ALL));
IGRAPH_FINALLY(igraph_adjlist_destroy, &clqdata.adj_list);
clqdata.IS = igraph_Calloc(no_of_nodes, igraph_integer_t);
if (clqdata.IS == 0)
IGRAPH_ERROR("igraph_i_maximal_or_largest_cliques_or_indsets failed", IGRAPH_ENOMEM);
IGRAPH_FINALLY(igraph_free, clqdata.IS);
IGRAPH_VECTOR_INIT_FINALLY(&clqdata.deg, no_of_nodes);
for (i=0; i<no_of_nodes; i++)
VECTOR(clqdata.deg)[i] = igraph_vector_size(igraph_adjlist_get(&clqdata.adj_list, i));
clqdata.buckets = igraph_Calloc(no_of_nodes+1, igraph_set_t);
if (clqdata.buckets == 0)
IGRAPH_ERROR("igraph_maximal_or_largest_cliques_or_indsets failed", IGRAPH_ENOMEM);
IGRAPH_FINALLY(igraph_i_free_set_array, clqdata.buckets);
for (i=0; i<no_of_nodes; i++)
IGRAPH_CHECK(igraph_set_init(&clqdata.buckets[i], 0));
if (res) igraph_vector_ptr_clear(res);
/* Do the show */
clqdata.largest_set_size=0;
IGRAPH_CHECK(igraph_i_maximal_independent_vertex_sets_backtrack(graph, res, &clqdata, 0));
/* Cleanup */
for (i=0; i<no_of_nodes; i++) igraph_set_destroy(&clqdata.buckets[i]);
igraph_adjlist_destroy(&clqdata.adj_list);
igraph_vector_destroy(&clqdata.deg);
igraph_free(clqdata.IS);
igraph_free(clqdata.buckets);
IGRAPH_FINALLY_CLEAN(4);
if (clique_number) *clique_number = clqdata.largest_set_size;
return 0;
}
int igraph_random_walk(const igraph_t *graph, igraph_vector_t *walk,
igraph_integer_t start, igraph_neimode_t mode,
igraph_integer_t steps,
igraph_random_walk_stuck_t stuck) {
/* TODO:
- multiple walks potentially from multiple start vertices
- weights
*/
igraph_lazy_adjlist_t adj;
igraph_integer_t vc = igraph_vcount(graph);
igraph_integer_t i;
if (start < 0 || start >= vc) {
IGRAPH_ERROR("Invalid start vertex", IGRAPH_EINVAL);
}
if (steps < 0) {
IGRAPH_ERROR("Invalid number of steps", IGRAPH_EINVAL);
}
IGRAPH_CHECK(igraph_lazy_adjlist_init(graph, &adj, mode,
IGRAPH_DONT_SIMPLIFY));
IGRAPH_FINALLY(igraph_lazy_adjlist_destroy, &adj);
IGRAPH_CHECK(igraph_vector_resize(walk, steps));
RNG_BEGIN();
VECTOR(*walk)[0] = start;
for (i = 1; i < steps; i++) {
igraph_vector_t *neis;
igraph_integer_t nn;
neis = igraph_lazy_adjlist_get(&adj, start);
nn = igraph_vector_size(neis);
if (IGRAPH_UNLIKELY(nn == 0)) {
igraph_vector_resize(walk, i);
if (stuck == IGRAPH_RANDOM_WALK_STUCK_RETURN) {
break;
} else {
IGRAPH_ERROR("Random walk got stuck", IGRAPH_ERWSTUCK);
}
}
start = VECTOR(*walk)[i] = VECTOR(*neis)[ RNG_INTEGER(0, nn - 1) ];
}
RNG_END();
igraph_lazy_adjlist_destroy(&adj);
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
/**
* \function igraph_is_matching
* Checks whether the given matching is valid for the given graph.
*
* This function checks a matching vector and verifies whether its length
* matches the number of vertices in the given graph, its values are between
* -1 (inclusive) and the number of vertices (exclusive), and whether there
* exists a corresponding edge in the graph for every matched vertex pair.
* For bipartite graphs, it also verifies whether the matched vertices are
* in different parts of the graph.
*
* \param graph The input graph. It can be directed but the edge directions
* will be ignored.
* \param types If the graph is bipartite and you are interested in bipartite
* matchings only, pass the vertex types here. If the graph is
* non-bipartite, simply pass \c NULL.
* \param matching The matching itself. It must be a vector where element i
* contains the ID of the vertex that vertex i is matched to,
* or -1 if vertex i is unmatched.
* \param result Pointer to a boolean variable, the result will be returned
* here.
*
* \sa \ref igraph_is_maximal_matching() if you are also interested in whether
* the matching is maximal (i.e. non-extendable).
*
* Time complexity: O(|V|+|E|) where |V| is the number of vertices and
* |E| is the number of edges.
*
* \example examples/simple/igraph_maximum_bipartite_matching.c
*/
int igraph_is_matching(const igraph_t* graph,
const igraph_vector_bool_t* types, const igraph_vector_long_t* matching,
igraph_bool_t* result) {
long int i, j, no_of_nodes = igraph_vcount(graph);
igraph_bool_t conn;
/* Checking match vector length */
if (igraph_vector_long_size(matching) != no_of_nodes) {
*result = 0; return IGRAPH_SUCCESS;
}
for (i = 0; i < no_of_nodes; i++) {
j = VECTOR(*matching)[i];
/* Checking range of each element in the match vector */
if (j < -1 || j >= no_of_nodes) {
*result = 0; return IGRAPH_SUCCESS;
}
/* When i is unmatched, we're done */
if (j == -1)
continue;
/* Matches must be mutual */
if (VECTOR(*matching)[j] != i) {
*result = 0; return IGRAPH_SUCCESS;
}
/* Matched vertices must be connected */
IGRAPH_CHECK(igraph_are_connected(graph, (igraph_integer_t) i,
(igraph_integer_t) j, &conn));
if (!conn) {
/* Try the other direction -- for directed graphs */
IGRAPH_CHECK(igraph_are_connected(graph, (igraph_integer_t) j,
(igraph_integer_t) i, &conn));
if (!conn) {
*result = 0; return IGRAPH_SUCCESS;
}
}
}
if (types != 0) {
/* Matched vertices must be of different types */
for (i = 0; i < no_of_nodes; i++) {
j = VECTOR(*matching)[i];
if (j == -1)
continue;
if (VECTOR(*types)[i] == VECTOR(*types)[j]) {
*result = 0; return IGRAPH_SUCCESS;
}
}
}
*result = 1;
return IGRAPH_SUCCESS;
}
/**
* \ingroup structural
* \function igraph_similarity_jaccard
* \brief Jaccard similarity coefficient for the given vertices.
*
* </para><para>
* The Jaccard similarity coefficient of two vertices is the number of common
* neighbors divided by the number of vertices that are neighbors of at
* least one of the two vertices being considered. This function calculates
* the pairwise Jaccard similarities for some (or all) of the vertices.
*
* \param graph The graph object to analyze
* \param res Pointer to a matrix, the result of the calculation will
* be stored here. The number of its rows and columns is the same
* as the number of vertex ids in \p vids.
* \param vids The vertex ids of the vertices for which the
* calculation will be done.
* \param mode The type of neighbors to be used for the calculation in
* directed graphs. Possible values:
* \clist
* \cli IGRAPH_OUT
* the outgoing edges will be considered for each node.
* \cli IGRAPH_IN
* the incoming edges will be considered for each node.
* \cli IGRAPH_ALL
* the directed graph is considered as an undirected one for the
* computation.
* \endclist
* \param loops Whether to include the vertices themselves in the neighbor
* sets.
* \return Error code:
* \clist
* \cli IGRAPH_ENOMEM
* not enough memory for temporary data.
* \cli IGRAPH_EINVVID
* invalid vertex id passed.
* \cli IGRAPH_EINVMODE
* invalid mode argument.
* \endclist
*
* Time complexity: O(|V|^2 d),
* |V| is the number of vertices in the vertex iterator given, d is the
* (maximum) degree of the vertices in the graph.
*
* \sa \ref igraph_similarity_dice(), a measure very similar to the Jaccard
* coefficient
*
* \example examples/simple/igraph_similarity.c
*/
int igraph_similarity_jaccard(const igraph_t *graph, igraph_matrix_t *res,
const igraph_vs_t vids, igraph_neimode_t mode, igraph_bool_t loops) {
igraph_lazy_adjlist_t al;
igraph_vit_t vit, vit2;
long int i, j, k;
long int len_union, len_intersection;
igraph_vector_t *v1, *v2;
IGRAPH_CHECK(igraph_vit_create(graph, vids, &vit));
IGRAPH_FINALLY(igraph_vit_destroy, &vit);
IGRAPH_CHECK(igraph_vit_create(graph, vids, &vit2));
IGRAPH_FINALLY(igraph_vit_destroy, &vit2);
IGRAPH_CHECK(igraph_lazy_adjlist_init(graph, &al, mode, IGRAPH_SIMPLIFY));
IGRAPH_FINALLY(igraph_lazy_adjlist_destroy, &al);
IGRAPH_CHECK(igraph_matrix_resize(res, IGRAPH_VIT_SIZE(vit), IGRAPH_VIT_SIZE(vit)));
if (loops) {
for (IGRAPH_VIT_RESET(vit); !IGRAPH_VIT_END(vit); IGRAPH_VIT_NEXT(vit)) {
i=IGRAPH_VIT_GET(vit);
v1=igraph_lazy_adjlist_get(&al, (igraph_integer_t) i);
if (!igraph_vector_binsearch(v1, i, &k))
igraph_vector_insert(v1, k, i);
}
}
for (IGRAPH_VIT_RESET(vit), i=0;
!IGRAPH_VIT_END(vit); IGRAPH_VIT_NEXT(vit), i++) {
MATRIX(*res, i, i) = 1.0;
for (IGRAPH_VIT_RESET(vit2), j=0;
!IGRAPH_VIT_END(vit2); IGRAPH_VIT_NEXT(vit2), j++) {
if (j <= i)
continue;
v1=igraph_lazy_adjlist_get(&al, IGRAPH_VIT_GET(vit));
v2=igraph_lazy_adjlist_get(&al, IGRAPH_VIT_GET(vit2));
igraph_i_neisets_intersect(v1, v2, &len_union, &len_intersection);
if (len_union > 0)
MATRIX(*res, i, j) = ((igraph_real_t)len_intersection)/len_union;
else
MATRIX(*res, i, j) = 0.0;
MATRIX(*res, j, i) = MATRIX(*res, i, j);
}
}
igraph_lazy_adjlist_destroy(&al);
igraph_vit_destroy(&vit);
igraph_vit_destroy(&vit2);
IGRAPH_FINALLY_CLEAN(3);
return 0;
}
int igraph_is_connected_weak(const igraph_t *graph, igraph_bool_t *res) {
long int no_of_nodes=igraph_vcount(graph);
char *already_added;
igraph_vector_t neis=IGRAPH_VECTOR_NULL;
igraph_dqueue_t q=IGRAPH_DQUEUE_NULL;
long int i, j;
if (no_of_nodes == 0) {
*res = 1;
return IGRAPH_SUCCESS;
}
already_added=igraph_Calloc(no_of_nodes, char);
if (already_added==0) {
IGRAPH_ERROR("is connected (weak) failed", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(free, already_added); /* TODO: hack */
IGRAPH_DQUEUE_INIT_FINALLY(&q, 10);
IGRAPH_VECTOR_INIT_FINALLY(&neis, 0);
/* Try to find at least two clusters */
already_added[0]=1;
IGRAPH_CHECK(igraph_dqueue_push(&q, 0));
j=1;
while ( !igraph_dqueue_empty(&q)) {
long int actnode=(long int) igraph_dqueue_pop(&q);
IGRAPH_ALLOW_INTERRUPTION();
IGRAPH_CHECK(igraph_neighbors(graph, &neis, (igraph_integer_t) actnode,
IGRAPH_ALL));
for (i=0; i <igraph_vector_size(&neis); i++) {
long int neighbor=(long int) VECTOR(neis)[i];
if (already_added[neighbor] != 0) { continue; }
IGRAPH_CHECK(igraph_dqueue_push(&q, neighbor));
j++;
already_added[neighbor]++;
}
}
/* Connected? */
*res = (j == no_of_nodes);
igraph_Free(already_added);
igraph_dqueue_destroy(&q);
igraph_vector_destroy(&neis);
IGRAPH_FINALLY_CLEAN(3);
return 0;
}
int igraph_biguint_mul_limb(igraph_biguint_t *res, igraph_biguint_t *b,
limb_t l) {
long int nlimb=igraph_biguint_size(b);
limb_t carry;
if (res!= b) { IGRAPH_CHECK(igraph_biguint_resize(res, nlimb)); }
carry=bn_mul_limb( VECTOR(res->v), VECTOR(b->v), l, nlimb);
if (carry) {
IGRAPH_CHECK(igraph_biguint_extend(res, carry));
}
return 0;
}
int igraph_i_maximal_cliques_store(const igraph_vector_t* clique, void* data, igraph_bool_t* cont) {
igraph_vector_ptr_t* result = (igraph_vector_ptr_t*)data;
igraph_vector_t* vec;
vec = igraph_Calloc(1, igraph_vector_t);
if (vec == 0)
IGRAPH_ERROR("cannot allocate memory for storing next clique", IGRAPH_ENOMEM);
IGRAPH_CHECK(igraph_vector_copy(vec, clique));
IGRAPH_CHECK(igraph_vector_ptr_push_back(result, vec));
return IGRAPH_SUCCESS;
}
int igraph_is_minimal_separator(const igraph_t *graph,
const igraph_vs_t candidate,
igraph_bool_t *res) {
long int no_of_nodes=igraph_vcount(graph);
igraph_vector_bool_t removed;
igraph_dqueue_t Q;
igraph_vector_t neis;
long int candsize;
igraph_vit_t vit;
IGRAPH_CHECK(igraph_vit_create(graph, candidate, &vit));
IGRAPH_FINALLY(igraph_vit_destroy, &vit);
candsize=IGRAPH_VIT_SIZE(vit);
IGRAPH_CHECK(igraph_vector_bool_init(&removed, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_bool_destroy, &removed);
IGRAPH_CHECK(igraph_dqueue_init(&Q, 100));
IGRAPH_FINALLY(igraph_dqueue_destroy, &Q);
IGRAPH_VECTOR_INIT_FINALLY(&neis, 0);
/* Is it a separator at all? */
IGRAPH_CHECK(igraph_i_is_separator(graph, &vit, -1, res, &removed,
&Q, &neis, no_of_nodes));
if (!(*res)) {
/* Not a separator at all, nothing to do, *res is already set */
} else if (candsize == 0) {
/* Nothing to do, minimal, *res is already set */
} else {
/* General case, we need to remove each vertex from 'candidate'
* and check whether the remainder is a separator. If this is
* false for all vertices, then 'candidate' is a minimal
* separator.
*/
long int i;
for (i=0, *res=0; i<candsize && (!*res); i++) {
igraph_vector_bool_null(&removed);
IGRAPH_CHECK(igraph_i_is_separator(graph, &vit, i, res, &removed,
&Q, &neis, no_of_nodes));
}
(*res) = (*res) ? 0 : 1; /* opposite */
}
igraph_vector_destroy(&neis);
igraph_dqueue_destroy(&Q);
igraph_vector_bool_destroy(&removed);
igraph_vit_destroy(&vit);
IGRAPH_FINALLY_CLEAN(4);
return 0;
}
int igraph_vector_complex_realimag(const igraph_vector_complex_t *v,
igraph_vector_t *real,
igraph_vector_t *imag) {
int i, n=igraph_vector_complex_size(v);
IGRAPH_CHECK(igraph_vector_resize(real, n));
IGRAPH_CHECK(igraph_vector_resize(imag, n));
for (i=0; i<n; i++) {
igraph_complex_t z=VECTOR(*v)[i];
VECTOR(*real)[i] = IGRAPH_REAL(z);
VECTOR(*imag)[i] = IGRAPH_IMAG(z);
}
return 0;
}
int igraph_create_bipartite(igraph_t *graph, const igraph_vector_bool_t *types,
const igraph_vector_t *edges,
igraph_bool_t directed) {
igraph_integer_t no_of_nodes=
(igraph_integer_t) igraph_vector_bool_size(types);
long int no_of_edges=igraph_vector_size(edges);
igraph_real_t min_edge=0, max_edge=0;
igraph_bool_t min_type=0, max_type=0;
long int i;
if (no_of_edges % 2 != 0) {
IGRAPH_ERROR("Invalid (odd) edges vector", IGRAPH_EINVEVECTOR);
}
no_of_edges /= 2;
if (no_of_edges != 0) {
igraph_vector_minmax(edges, &min_edge, &max_edge);
}
if (min_edge < 0 || max_edge >= no_of_nodes) {
IGRAPH_ERROR("Invalid (negative) vertex id", IGRAPH_EINVVID);
}
/* Check types vector */
if (no_of_nodes != 0) {
igraph_vector_bool_minmax(types, &min_type, &max_type);
if (min_type < 0 || max_type > 1) {
IGRAPH_WARNING("Non-binary type vector when creating a bipartite graph");
}
}
/* Check bipartiteness */
for (i=0; i<no_of_edges*2; i+=2) {
long int from=(long int) VECTOR(*edges)[i];
long int to=(long int) VECTOR(*edges)[i+1];
long int t1=VECTOR(*types)[from];
long int t2=VECTOR(*types)[to];
if ( (t1 && t2) || (!t1 && !t2) ) {
IGRAPH_ERROR("Invalid edges, not a bipartite graph", IGRAPH_EINVAL);
}
}
IGRAPH_CHECK(igraph_empty(graph, no_of_nodes, directed));
IGRAPH_FINALLY(igraph_destroy, graph);
IGRAPH_CHECK(igraph_add_edges(graph, edges, 0));
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
int igraph_dot_product_game(igraph_t *graph, const igraph_matrix_t *vecs,
igraph_bool_t directed) {
igraph_integer_t nrow=igraph_matrix_nrow(vecs);
igraph_integer_t ncol=igraph_matrix_ncol(vecs);
int i, j;
igraph_vector_t edges;
igraph_bool_t warned_neg=0, warned_big=0;
IGRAPH_VECTOR_INIT_FINALLY(&edges, 0);
RNG_BEGIN();
for (i = 0; i < ncol; i++) {
int from=directed ? 0 : i+1;
igraph_vector_t v1;
igraph_vector_view(&v1, &MATRIX(*vecs, 0, i), nrow);
for (j = from; j < ncol; j++) {
igraph_real_t prob;
igraph_vector_t v2;
if (i==j) { continue; }
igraph_vector_view(&v2, &MATRIX(*vecs, 0, j), nrow);
igraph_lapack_ddot(&v1, &v2, &prob);
if (prob < 0 && ! warned_neg) {
warned_neg=1;
IGRAPH_WARNING("Negative connection probability in "
"dot-product graph");
} else if (prob > 1 && ! warned_big) {
warned_big=1;
IGRAPH_WARNING("Greater than 1 connection probability in "
"dot-product graph");
IGRAPH_CHECK(igraph_vector_push_back(&edges, i));
IGRAPH_CHECK(igraph_vector_push_back(&edges, j));
} else if (RNG_UNIF01() < prob) {
IGRAPH_CHECK(igraph_vector_push_back(&edges, i));
IGRAPH_CHECK(igraph_vector_push_back(&edges, j));
}
}
}
RNG_END();
igraph_create(graph, &edges, ncol, directed);
igraph_vector_destroy(&edges);
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
/*
* Converts a Java VertexSet to an igraph_vs_t
* @return: zero if everything went fine, 1 if a null pointer was passed
*/
int Java_net_sf_igraph_VertexSet_to_igraph_vs(JNIEnv *env, jobject jobj, igraph_vs_t *result) {
jint typeHint;
jobject idArray;
if (jobj == 0) {
IGRAPH_CHECK(igraph_vs_all(result));
return IGRAPH_SUCCESS;
}
typeHint = (*env)->CallIntMethod(env, jobj, net_sf_igraph_VertexSet_getTypeHint_mid);
if (typeHint != 1 && typeHint != 2) {
IGRAPH_CHECK(igraph_vs_all(result));
return IGRAPH_SUCCESS;
}
idArray = (*env)->CallObjectMethod(env, jobj, net_sf_igraph_VertexSet_getIdArray_mid);
if ((*env)->ExceptionCheck(env)) {
return IGRAPH_EINVAL;
}
if (typeHint == 1) {
/* Single vertex */
jlong id[1];
(*env)->GetLongArrayRegion(env, idArray, 0, 1, id);
IGRAPH_CHECK(igraph_vs_1(result, (igraph_integer_t)id[0]));
} else if (typeHint == 2) {
/* List of vertices */
jlong* ids;
igraph_vector_t vec;
long i, n;
ids = (*env)->GetLongArrayElements(env, idArray, 0);
n = (*env)->GetArrayLength(env, idArray);
IGRAPH_VECTOR_INIT_FINALLY(&vec, n);
for (i = 0; i < n; i++)
VECTOR(vec)[i] = ids[i];
IGRAPH_CHECK(igraph_vs_vector_copy(result, &vec));
igraph_vector_destroy(&vec);
IGRAPH_FINALLY_CLEAN(1);
(*env)->ReleaseLongArrayElements(env, idArray, ids, JNI_ABORT);
}
(*env)->DeleteLocalRef(env, idArray);
return IGRAPH_SUCCESS;
}
int igraph_i_local_scan_1_directed(const igraph_t *graph,
igraph_vector_t *res,
const igraph_vector_t *weights,
igraph_neimode_t mode) {
int no_of_nodes=igraph_vcount(graph);
igraph_inclist_t incs;
int i, node;
igraph_vector_int_t neis;
IGRAPH_CHECK(igraph_inclist_init(graph, &incs, mode));
IGRAPH_FINALLY(igraph_inclist_destroy, &incs);
igraph_vector_int_init(&neis, no_of_nodes);
IGRAPH_FINALLY(igraph_vector_int_destroy, &neis);
igraph_vector_resize(res, no_of_nodes);
igraph_vector_null(res);
for (node=0; node < no_of_nodes; node++) {
igraph_vector_int_t *edges1=igraph_inclist_get(&incs, node);
int edgeslen1=igraph_vector_int_size(edges1);
IGRAPH_ALLOW_INTERRUPTION();
/* Mark neighbors and self*/
VECTOR(neis)[node] = node+1;
for (i=0; i<edgeslen1; i++) {
int e=VECTOR(*edges1)[i];
int nei=IGRAPH_OTHER(graph, e, node);
igraph_real_t w= weights ? VECTOR(*weights)[e] : 1;
VECTOR(neis)[nei] = node+1;
VECTOR(*res)[node] += w;
}
/* Crawl neighbors */
for (i=0; i<edgeslen1; i++) {
int e2=VECTOR(*edges1)[i];
int nei=IGRAPH_OTHER(graph, e2, node);
igraph_vector_int_t *edges2=igraph_inclist_get(&incs, nei);
int j, edgeslen2=igraph_vector_int_size(edges2);
for (j=0; j<edgeslen2; j++) {
int e2=VECTOR(*edges2)[j];
int nei2=IGRAPH_OTHER(graph, e2, nei);
igraph_real_t w2= weights ? VECTOR(*weights)[e2] : 1;
if (VECTOR(neis)[nei2] == node+1) {
VECTOR(*res)[node] += w2;
}
}
}
} /* node < no_of_nodes */
igraph_vector_int_destroy(&neis);
igraph_inclist_destroy(&incs);
IGRAPH_FINALLY_CLEAN(2);
return 0;
}
