TEST_F(TestPathFinder, StringsWithMoreThanOneDiffCharAreNotAdjacent)
{
EXPECT_FALSE(are_adjacent("abda", "abcb"));
EXPECT_FALSE(are_adjacent("abca", "abdb"));
EXPECT_FALSE(are_adjacent("abdaa", "abcba"));
EXPECT_FALSE(are_adjacent("abcaa", "abdba"));
}
TEST_F(TestPathFinder, StringsWithOneDiffCharAreAdjacent)
{
EXPECT_TRUE(are_adjacent("abd", "abc"));
EXPECT_TRUE(are_adjacent("abc", "abd"));
EXPECT_TRUE(are_adjacent("abdaa", "abcaa"));
EXPECT_TRUE(are_adjacent("abcaa", "abdaa"));
}
/**
* Remove the edge connecting n to m. Will fail if are_adjacent() returns false.
*
* @param[in] n index of the first vertex.
* @param[in] m index of the second vertex.
*/
void base::remove_edge(const vertices_size_type &n, const vertices_size_type &m)
{
if (!are_adjacent(n,m)) {
pagmo_throw(value_error,"cannot remove edge, vertices are not connected");
}
boost::remove_edge(boost::vertex(n,m_graph),boost::vertex(m,m_graph),m_graph);
}
/**
* Add an edge connecting n to m. Will fail if are_adjacent() returns true.
*
* @param[in] n index of the first vertex.
* @param[in] m index of the second vertex.
*/
void base::add_edge(const vertices_size_type &n, const vertices_size_type &m)
{
if (are_adjacent(n,m)) {
pagmo_throw(value_error,"cannot add edge, vertices are already connected");
}
const std::pair<e_descriptor,bool> result = boost::add_edge(boost::vertex(n,m_graph),boost::vertex(m,m_graph),m_graph);
pagmo_assert(result.second);
// Assign weight 1 to the edge.
boost::property_map<graph_type,boost::edge_weight_t>::type w = boost::get(boost::edge_weight,m_graph);
w[result.first] = 1;
}
void Vertex_visibility_graph_2<Traits>::handle(Tree_iterator p,
Tree_iterator q,
const Polygon& polygon,
Vertex_map& vertex_map)
{
#ifdef CGAL_VISIBILITY_GRAPH_DEBUG
std::cout << "Handling edge from " << (*p).x() << " " << (*p).y()
<< " to " << (*q).x() << " " << (*q).y() << std::endl;
#endif
Vertex_map_iterator p_it = vertex_map.find(*p);
Vertex_map_iterator q_it = vertex_map.find(*q);
CGAL_assertion (p_it != vertex_map.end());
CGAL_assertion (q_it != vertex_map.end());
#ifdef CGAL_VISIBILITY_GRAPH_DEBUG
std::cout << "p currently sees : ";
if ((*p_it).second.second != polygon.end())
std::cout << *((*p_it).second.second) << endl;
else
std::cout << " NADA" << endl;
#endif
// if p and q are adjacent
if (are_adjacent(polygon, (*p_it).second.first, (*q_it).second.first))
{
#ifdef CGAL_VISIBILITY_GRAPH_DEBUG
cout << "are adjacent" << endl;
#endif
insert_edge(Point_pair(*p,*q));
update_visibility(p_it, q_it, polygon, 1);
}
else
{
bool interior_at_p = diagonal_in_interior(polygon, (*p_it).second.first,
(*q_it).second.first);
bool interior_at_q = diagonal_in_interior(polygon, (*q_it).second.first,
(*p_it).second.first);
// line of site is through the interior of the polygon
if (interior_at_p && interior_at_q)
{
#ifdef CGAL_VISIBILITY_GRAPH_DEBUG
cout << "both interior" << endl;
#endif
// if p sees something and q is visible only through collinear
// points then update p's visibility if one of the points adjacent
// to q is above the line unless p's current visibility point
// obscures the view.
if ((*p_it).second.second != polygon.end() &&
are_strictly_ordered_along_line_2((*p_it).first,
*(*p_it).second.second,
(*q_it).first))
{
update_collinear_visibility(p_it, q_it, polygon);
}
// p current sees nothing or q is visible to p
else if ((*p_it).second.second == polygon.end() ||
point_is_visible(polygon, (*q_it).second.first, p_it))
{
insert_edge(Point_pair(*p,*q));
update_visibility(p_it, q_it, polygon, 0);
}
}
else if (!interior_at_p && !interior_at_q) // both points exterior
{
#ifdef CGAL_VISIBILITY_GRAPH_DEBUG
cout << "both exterior" << endl;
#endif
// p currently sees nothing or q is visible to p
if ((*p_it).second.second == polygon.end() ||
point_is_visible(polygon, (*q_it).second.first, p_it))
{
(*p_it).second.second = (*q_it).second.first;
}
}
}
#ifdef CGAL_VISIBILITY_GRAPH_DEBUG
std::cout << "p now sees : ";
if ((*p_it).second.second != polygon.end())
std::cout << *((*p_it).second.second) << endl;
else
std::cout << " NADA" << endl;
#endif
}
void clustered_ba::connect(const vertices_size_type &idx)
{
pagmo_assert(get_number_of_vertices() > 0);
const vertices_size_type prev_size = get_number_of_vertices() - 1;
if (prev_size < m_m0) {
// If we had not built the initial m0 nodes, do it.
// We want to connect the newcomer island with high probability, and make sure that
// at least one connection exists (otherwise the island stays isolated).
// NOTE: is it worth to make it a user-tunable parameter?
const double prob = 0.0;
// Flag indicating if at least 1 connection was added.
bool connection_added = false;
// Main loop.
for (std::pair<v_iterator,v_iterator> vertices = get_vertices(); vertices.first != vertices.second; ++vertices.first) {
// Do not consider the new vertex itself.
if (*vertices.first != idx) {
if (m_drng() < prob) {
connection_added = true;
// Add the connections
add_edge(*vertices.first,idx);
add_edge(idx,*vertices.first);
}
}
}
// If no connections were established and this is not the first island being inserted,
// establish at least one connection with a random island other than n.
if ((!connection_added) && (prev_size != 0)) {
// Get a random vertex index between 0 and n_vertices - 1. Keep on repeating the procedure if by
// chance we end up on idx again.
boost::uniform_int<vertices_size_type> uni_int(0,get_number_of_vertices() - 1);
vertices_size_type rnd;
do {
rnd = uni_int(m_urng);
} while (rnd == idx);
// Add connections to the random vertex.
add_edge(rnd,idx);
add_edge(idx,rnd);
}
} else {
// Now we need to add j edges, choosing the nodes with a probability
// proportional to their number of connections. We keep track of the
// connection established in order to avoid connecting twice to the same
// node.
// j is a random integer in the range 1 to m.
boost::uniform_int<edges_size_type> uni_int2(1,m_m);
std::size_t i = 0;
std::size_t j = uni_int2(m_urng);
std::pair<v_iterator,v_iterator> vertices;
std::pair<a_iterator,a_iterator> adj_vertices;
while (i < j) {
// Let's find the current total number of edges.
const edges_size_type n_edges = get_number_of_edges();
pagmo_assert(n_edges > 0);
boost::uniform_int<edges_size_type> uni_int(0,n_edges - 1 - i);
// Here we choose a random number between 0 and n_edges - 1 - i.
const edges_size_type rn = uni_int(m_urng);
edges_size_type n = 0;
// Iterate over all vertices and accumulate the number of edges for each of them. Stop when the accumulated number of edges is greater
// than rn. This is equivalent to giving a chance of connection to vertex v directly proportional to the number of edges departing from v.
// You can think of this process as selecting a random edge among all the existing edges and connecting to the vertex from which the
// selected edge departs.
vertices = get_vertices();
for (; vertices.first != vertices.second; ++vertices.first) {
// Do not consider it_n.
if (*vertices.first != idx) {
adj_vertices = get_adjacent_vertices(*vertices.first);
n += boost::numeric_cast<edges_size_type>(std::distance(adj_vertices.first,adj_vertices.second));
if (n > rn) {
break;
}
}
}
pagmo_assert(vertices.first != vertices.second);
// If the candidate was not already connected, then add it.
if (!are_adjacent(idx,*vertices.first)) {
// Connect to nodes that are already adjacent to idx with probability p.
// This step increases clustering in the network.
adj_vertices = get_adjacent_vertices(idx);
for(;adj_vertices.first != adj_vertices.second; ++adj_vertices.first) {
if(m_drng() < m_p && *adj_vertices.first != *vertices.first && !are_adjacent(*adj_vertices.first,*vertices.first)) {
add_edge(*adj_vertices.first, *vertices.first);
add_edge(*vertices.first, *adj_vertices.first);
}
}
// Connect to idx
add_edge(*vertices.first,idx);
add_edge(idx,*vertices.first);
++i;
}
}
}
}
TEST_F(TestPathFinder, EqualStringsAreNotAdjacent)
{
EXPECT_FALSE(are_adjacent("abc", "abc"));
}
TEST_F(TestPathFinder, StringsWithDiffLenAreNotAdjacent)
{
EXPECT_FALSE(are_adjacent("ab", "abc"));
}
TEST_F(TestPathFinder, EmptyStringsAndNonEmptyStringAreNotAdjacent)
{
EXPECT_FALSE(are_adjacent("a", ""));
EXPECT_FALSE(are_adjacent("", "b"));
}
