/**
* \ingroup python_interface_edgeseq
* \brief Initialize a new edge sequence object for a given graph
* \return the initialized PyObject
*/
int igraphmodule_EdgeSeq_init(igraphmodule_EdgeSeqObject *self,
PyObject *args, PyObject *kwds) {
static char *kwlist[] = { "graph", "edges", NULL };
PyObject *g, *esobj=Py_None;
igraph_es_t es;
if (!PyArg_ParseTupleAndKeywords(args, kwds, "O!|O", kwlist,
&igraphmodule_GraphType, &g, &esobj))
return -1;
if (esobj == Py_None) {
/* If es is None, we are selecting all the edges */
igraph_es_all(&es, IGRAPH_EDGEORDER_ID);
} else if (PyInt_Check(esobj)) {
/* We selected a single edge */
long int idx = PyInt_AsLong(esobj);
if (idx < 0 || idx >= igraph_ecount(&((igraphmodule_GraphObject*)g)->g)) {
PyErr_SetString(PyExc_ValueError, "edge index out of range");
return -1;
}
igraph_es_1(&es, (igraph_integer_t)idx);
} else {
/* We selected multiple edges */
igraph_vector_t v;
igraph_integer_t n = igraph_ecount(&((igraphmodule_GraphObject*)g)->g);
if (igraphmodule_PyObject_to_vector_t(esobj, &v, 1))
return -1;
if (!igraph_vector_isininterval(&v, 0, n-1)) {
igraph_vector_destroy(&v);
PyErr_SetString(PyExc_ValueError, "edge index out of range");
return -1;
}
if (igraph_es_vector_copy(&es, &v)) {
igraphmodule_handle_igraph_error();
igraph_vector_destroy(&v);
return -1;
}
igraph_vector_destroy(&v);
}
self->es = es;
Py_INCREF(g);
self->gref = (igraphmodule_GraphObject*)g;
return 0;
}
/**
* \ingroup python_interface_vertexseq
* \brief Initialize a new vertex sequence object for a given graph
* \return the initialized PyObject
*/
int igraphmodule_VertexSeq_init(igraphmodule_VertexSeqObject *self,
PyObject *args, PyObject *kwds) {
static char *kwlist[] = { "graph", "vertices", NULL };
PyObject *g, *vsobj=Py_None;
igraph_vs_t vs;
if (!PyArg_ParseTupleAndKeywords(args, kwds, "O!|O", kwlist,
&igraphmodule_GraphType, &g, &vsobj))
return -1;
if (vsobj == Py_None) {
/* If vs is None, we are selecting all the vertices */
igraph_vs_all(&vs);
} else if (PyInt_Check(vsobj)) {
/* We selected a single vertex */
long int idx = PyInt_AsLong(vsobj);
if (idx < 0 || idx >= igraph_vcount(&((igraphmodule_GraphObject*)g)->g)) {
PyErr_SetString(PyExc_ValueError, "vertex index out of range");
return -1;
}
igraph_vs_1(&vs, (igraph_integer_t)idx);
} else {
igraph_vector_t v;
igraph_integer_t n = igraph_vcount(&((igraphmodule_GraphObject*)g)->g);
if (igraphmodule_PyObject_to_vector_t(vsobj, &v, 1))
return -1;
if (!igraph_vector_isininterval(&v, 0, n-1)) {
igraph_vector_destroy(&v);
PyErr_SetString(PyExc_ValueError, "vertex index out of range");
return -1;
}
if (igraph_vs_vector_copy(&vs, &v)) {
igraphmodule_handle_igraph_error();
igraph_vector_destroy(&v);
return -1;
}
igraph_vector_destroy(&v);
}
self->vs = vs;
Py_INCREF(g);
self->gref = (igraphmodule_GraphObject*)g;
return 0;
}
/**
* \ingroup interface
* \function igraph_add_edges
* \brief Adds edges to a graph object.
*
* </para><para>
* The edges are given in a vector, the
* first two elements define the first edge (the order is
* <code>from</code>, <code>to</code> for directed
* graphs). The vector
* should contain even number of integer numbers between zero and the
* number of vertices in the graph minus one (inclusive). If you also
* want to add new vertices, call igraph_add_vertices() first.
* \param graph The graph to which the edges will be added.
* \param edges The edges themselves.
* \param attr The attributes of the new edges, only used by high level
* interfaces currently, you can supply 0 here.
* \return Error code:
* \c IGRAPH_EINVEVECTOR: invalid (odd)
* edges vector length, \c IGRAPH_EINVVID:
* invalid vertex id in edges vector.
*
* This function invalidates all iterators.
*
* </para><para>
* Time complexity: O(|V|+|E|) where
* |V| is the number of vertices and
* |E| is the number of
* edges in the \em new, extended graph.
*/
int igraph_add_edges(igraph_t *graph, const igraph_vector_t *edges,
void *attr) {
long int no_of_edges=igraph_vector_size(&graph->from);
long int edges_to_add=igraph_vector_size(edges)/2;
long int i=0;
igraph_error_handler_t *oldhandler;
int ret1, ret2;
igraph_vector_t newoi, newii;
igraph_bool_t directed=igraph_is_directed(graph);
if (igraph_vector_size(edges) % 2 != 0) {
IGRAPH_ERROR("invalid (odd) length of edges vector", IGRAPH_EINVEVECTOR);
}
if (!igraph_vector_isininterval(edges, 0, igraph_vcount(graph)-1)) {
IGRAPH_ERROR("cannot add edges", IGRAPH_EINVVID);
}
/* from & to */
IGRAPH_CHECK(igraph_vector_reserve(&graph->from, no_of_edges+edges_to_add));
IGRAPH_CHECK(igraph_vector_reserve(&graph->to , no_of_edges+edges_to_add));
while (i<edges_to_add*2) {
if (directed || VECTOR(*edges)[i] > VECTOR(*edges)[i+1]) {
igraph_vector_push_back(&graph->from, VECTOR(*edges)[i++]); /* reserved */
igraph_vector_push_back(&graph->to, VECTOR(*edges)[i++]); /* reserved */
} else {
igraph_vector_push_back(&graph->to, VECTOR(*edges)[i++]); /* reserved */
igraph_vector_push_back(&graph->from, VECTOR(*edges)[i++]); /* reserved */
}
}
/* disable the error handler temporarily */
oldhandler=igraph_set_error_handler(igraph_error_handler_ignore);
/* oi & ii */
ret1=igraph_vector_init(&newoi, no_of_edges);
ret2=igraph_vector_init(&newii, no_of_edges);
if (ret1 != 0 || ret2 != 0) {
igraph_vector_resize(&graph->from, no_of_edges); /* gets smaller */
igraph_vector_resize(&graph->to, no_of_edges); /* gets smaller */
igraph_set_error_handler(oldhandler);
IGRAPH_ERROR("cannot add edges", IGRAPH_ERROR_SELECT_2(ret1, ret2));
}
ret1=igraph_vector_order(&graph->from, &graph->to, &newoi, graph->n);
ret2=igraph_vector_order(&graph->to , &graph->from, &newii, graph->n);
if (ret1 != 0 || ret2 != 0) {
igraph_vector_resize(&graph->from, no_of_edges);
igraph_vector_resize(&graph->to, no_of_edges);
igraph_vector_destroy(&newoi);
igraph_vector_destroy(&newii);
igraph_set_error_handler(oldhandler);
IGRAPH_ERROR("cannot add edges", IGRAPH_ERROR_SELECT_2(ret1, ret2));
}
/* Attributes */
if (graph->attr) {
ret1=igraph_i_attribute_add_edges(graph, edges, attr);
if (ret1 != 0) {
igraph_vector_resize(&graph->from, no_of_edges);
igraph_vector_resize(&graph->to, no_of_edges);
igraph_vector_destroy(&newoi);
igraph_vector_destroy(&newii);
igraph_set_error_handler(oldhandler);
IGRAPH_ERROR("cannot add edges", ret1);
}
}
/* os & is, its length does not change, error safe */
igraph_i_create_start(&graph->os, &graph->from, &newoi, graph->n);
igraph_i_create_start(&graph->is, &graph->to , &newii, graph->n);
/* everything went fine */
igraph_vector_destroy(&graph->oi);
igraph_vector_destroy(&graph->ii);
graph->oi=newoi;
graph->ii=newii;
igraph_set_error_handler(oldhandler);
return 0;
}
int igraph_get_eids(const igraph_t *graph, igraph_vector_t *eids,
const igraph_vector_t *pairs, igraph_bool_t directed) {
long int n=igraph_vector_size(pairs);
long int no_of_nodes=igraph_vcount(graph);
long int no_of_edges=igraph_ecount(graph);
igraph_bool_t *seen;
long int i;
igraph_integer_t eid=-1;
if (n % 2 != 0) {
IGRAPH_ERROR("Cannot get edge ids, invalid length of edge ids",
IGRAPH_EINVAL);
}
if (!igraph_vector_isininterval(pairs, 0, no_of_nodes-1)) {
IGRAPH_ERROR("Cannot get edge ids, invalid vertex id", IGRAPH_EINVVID);
}
seen=igraph_Calloc(no_of_edges, igraph_bool_t);
if (seen==0) {
IGRAPH_ERROR("Cannot get edge ids", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_free, seen);
IGRAPH_CHECK(igraph_vector_resize(eids, n/2));
if (igraph_is_directed(graph)) {
for (i=0; i<n/2; i++) {
long int from=VECTOR(*pairs)[2*i];
long int to=VECTOR(*pairs)[2*i+1];
eid=-1;
FIND_DIRECTED_EDGE(graph,from,to,&eid,seen);
if (!directed && eid < 0) {
FIND_DIRECTED_EDGE(graph,to,from,&eid,seen);
}
if (eid >= 0) {
VECTOR(*eids)[i]=eid;
seen[(long int)(eid)]=1;
} else {
IGRAPH_ERROR("Cannot get edge id, no such edge", IGRAPH_EINVAL);
}
}
} else {
for (i=0; i<n/2; i++) {
long int from=VECTOR(*pairs)[2*i];
long int to=VECTOR(*pairs)[2*i+1];
eid=-1;
FIND_UNDIRECTED_EDGE(graph,from,to,&eid,seen);
if (eid >= 0) {
VECTOR(*eids)[i]=eid;
seen[(long int)(eid)]=1;
} else {
IGRAPH_ERROR("Cannot get edge id, no such edge", IGRAPH_EINVAL);
}
}
}
igraph_Free(seen);
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
