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/* This file is part of the Gudhi Library. The Gudhi library
* (Geometric Understanding in Higher Dimensions) is a generic C++
* library for computational topology.
*
* Author(s): Siargey Kachanovich
*
* Copyright (C) 2015 INRIA Sophia Antipolis-Méditerranée (France)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef DIM_LISTS_H_
#define DIM_LISTS_H_
#include <boost/container/flat_map.hpp>
#include <boost/iterator/transform_iterator.hpp>
#include <algorithm>
#include <utility>
#include "gudhi/reader_utils.h"
#include "gudhi/distance_functions.h"
#include <gudhi/Dim_list_iterator.h>
#include <vector>
#include <list>
#include <set>
#include <queue>
#include <limits>
#include <math.h>
#include <ctime>
#include <iostream>
#include <boost/tuple/tuple.hpp>
#include <boost/iterator/zip_iterator.hpp>
#include <boost/iterator/counting_iterator.hpp>
#include <boost/range/iterator_range.hpp>
// Needed for the adjacency graph in bad link search
#include <boost/graph/graph_traits.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/connected_components.hpp>
namespace Gudhi {
namespace witness_complex {
/** \addtogroup simplex_tree
* Witness complex is a simplicial complex defined on two sets of points in \f$\mathbf{R}^D\f$:
* \f$W\f$ set of witnesses and \f$L \subseteq W\f$ set of landmarks. The simplices are based on points in \f$L\f$
* and a simplex belongs to the witness complex if and only if it is witnessed (there exists a point \f$w \in W\f$ such that
* w is closer to the vertices of this simplex than others) and all of its faces are witnessed as well.
*/
template< class Simplicial_complex >
class Dim_lists {
private:
typedef typename Simplicial_complex::Simplex_handle Simplex_handle;
typedef typename Gudhi::witness_complex::Dim_lists_iterator<Simplex_handle> Iterator;
std::vector<std::list<Simplex_handle>> table_;
Simplicial_complex& sc_;
public:
Dim_lists(Simplicial_complex & sc, int dim, double alpha_max = 100)
: sc_(sc)
{
table_ = std::vector<std::list<Simplex_handle>>(dim+1);
for (auto sh: sc.filtration_simplex_range()) {
if (sc_.filtration(sh) < alpha_max)
table_[sc.dimension(sh)].push_front(sh);
}
auto t_it = table_.rbegin();
while (t_it->empty()) {
t_it++;
table_.pop_back();
}
}
Iterator begin()
{
return Iterator(table_.rbegin()->begin(), table_.rbegin(), table_);
}
Iterator end()
{
return Iterator(table_[0].end(), table_.rend(), table_);
}
unsigned size()
{
unsigned curr_size = 0;
for (auto l: table_)
curr_size += l.size();
return curr_size;
}
bool is_face(Simplex_handle face, Simplex_handle coface)
{
// vertex range is sorted in decreasing order
auto fvr = sc_.simplex_vertex_range(face);
auto cfvr = sc_.simplex_vertex_range(coface);
auto fv_it = fvr.begin();
auto cfv_it = cfvr.begin();
while (fv_it != fvr.end() && cfv_it != cfvr.end()) {
if (*fv_it < *cfv_it)
++cfv_it;
else if (*fv_it == *cfv_it) {
++cfv_it;
++fv_it;
}
else
return false;
}
return (fv_it == fvr.end());
}
void output_simplices() {
std::cout << "Size of vector: " << size() << std::endl;
for (auto line_it = table_.rbegin(); line_it != table_.rend(); ++line_it)
for (auto sh: *line_it) {
std::cout << sc_.dimension(sh) << " ";
for (auto v : sc_.simplex_vertex_range(sh))
std::cout << v << " ";
std::cout << sc_.filtration(sh) << "\n";
}
}
void collapse()
{
auto coface_list_it = table_.rbegin();
auto face_list_it = table_.rbegin()+1;
for ( ;
face_list_it != table_.rend();
++face_list_it) {
auto face_it = face_list_it->begin();
while (face_it != face_list_it->end() && sc_.filtration(*face_it) != 0) {
int coface_count = 0;
auto reduced_coface = coface_list_it->begin();
for (auto coface_it = coface_list_it->begin(); coface_it != coface_list_it->end() && sc_.filtration(*coface_it) != 0; ++coface_it)
if (is_face(*face_it, *coface_it)) {
coface_count++;
if (coface_count == 1)
reduced_coface = coface_it;
else
break;
}
if (coface_count == 1) {
/*
std::cout << "Erase ( ";
for (auto v: sc_.simplex_vertex_range(*reduced_coface))
std::cout << v << " ";
*/
coface_list_it->erase(reduced_coface);
/*
std::cout << ") and then ( ";
for (auto v: sc_.simplex_vertex_range(*face_it))
std::cout << v << " ";
std::cout << ")\n";
*/
face_list_it->erase(face_it);
face_it = face_list_it->begin();
}
else
face_it++;
}
if ((coface_list_it++)->empty())
table_.pop_back();
}
}
bool is_pseudomanifold()
{
return true;
}
}; //class Dim_lists
} // namespace witness_complex
} // namespace Gudhi
#endif
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