11 #ifndef UTILS_EDGE_CONTRACTOR_H_
12 #define UTILS_EDGE_CONTRACTOR_H_
15 #include <gudhi/Skeleton_blocker_contractor.h>
16 #include <gudhi/Contraction/Edge_profile.h>
17 #include <gudhi/Contraction/policies/Cost_policy.h>
26 SkBlComplex& complex_;
27 unsigned num_contractions_;
32 template<
typename EdgeProfile>
class Length_cost :
public contraction::Cost_policy<EdgeProfile> {
34 typedef typename contraction::Cost_policy<EdgeProfile>::Cost_type Cost_type;
35 typedef typename EdgeProfile::Point Point;
37 Cost_type operator()(
const EdgeProfile& profile,
const boost::optional<Point>& placement)
const override {
41 return Geometry_trait::Squared_distance_d()(profile.p0(), profile.p1());
48 template<
typename EdgeProfile>
class Middle_placement :
public contraction::Placement_policy<EdgeProfile> {
50 typedef typename contraction::Placement_policy<EdgeProfile>::Placement_type Placement_type;
51 typedef typename EdgeProfile::Point Point;
53 Placement_type operator()(
const EdgeProfile& profile)
const override {
54 std::vector<double> mid_coords(profile.p0().dimension(), 0);
55 for (
int i = 0; i < profile.p0().dimension(); ++i) {
56 mid_coords[i] = (profile.p0()[i] + profile.p1()[i]) / 2.;
58 return Point(profile.p0().dimension(), mid_coords.begin(), mid_coords.end());
63 typedef typename SkBlComplex::Vertex_handle Vertex_handle;
64 typedef typename SkBlComplex::Edge_handle Edge_handle;
71 complex_(complex), num_contractions_(num_contractions) {
72 typedef typename contraction::Edge_profile<Complex> Profile;
73 num_contractions = (std::min)(
static_cast<int>(num_contractions),
static_cast<int>(complex_.num_vertices() - 1));
74 typedef typename contraction::Skeleton_blocker_contractor<Complex> Contractor;
75 Contractor contractor(complex_,
76 new Length_cost<contraction::Edge_profile < Complex >> (),
77 new Middle_placement<contraction::Edge_profile < Complex >> (),
78 contraction::make_link_valid_contraction<Profile>(),
79 contraction::make_remove_popable_blockers_visitor<Profile>());
80 contractor.contract_edges(num_contractions);
Definition: Edge_contractor.h:24
Edge_contractor(SkBlComplex &complex, unsigned num_contractions)
Modify complex to be the expansion of the k-nearest neighbor symetric graph.
Definition: Edge_contractor.h:70