/* 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): Clément Maria
*
* Copyright (C) 2014 Inria
*
* 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 .
*/
/** \brief The concept FilteredComplex describes the requirements
* for a type to implement a filtered cell complex, from which
* one can compute persistent homology via a model of the concept
* PersistentHomology.
*/
struct FilteredComplex
{
/** Handle to specify a simplex. */
typedef unspecified Simplex_handle;
/** \brief Type for the value of the filtration function.
*
* Must be comparable with <. */
typedef unspecified Filtration_value;
/** \brief Specifies the nature of the indexing scheme.
*
* is model of IndexingTag. */
typedef unspecified Indexing_tag;
/** Returns a Simplex_handle that is different from all simplex handles
* of the simplices. */
Simplex_handle null_simplex();
/** \brief Returns the number of simplices in the complex.
*
* Does not count the empty simplex. */
size_t num_simplices();
/** \brief Returns the dimension of a simplex. */
int dimension(Simplex_handle sh);
/** \brief Returns the filtration value of a simplex.
*
* If sh is null_simplex(), returns the maximal value of the
* filtration function on the complex. */
Filtration_value filtration(Simplex_handle sh);
/** \brief Returns the simplex that has index idx in the filtration.
*
* This is only called on valid indices. */
Simplex_handle simplex ( size_t idx );
/** \brief Iterator on the simplices belonging to the
* boundary of a simplex.
*
* value_type
must be 'Simplex_handle'.
*/
typedef unspecified Boundary_simplex_iterator;
/** \brief Range giving access to the simplices in the boundary of
* a simplex.
*
* .begin() and .end() return type Boundary_simplex_iterator.
*/
typedef unspecified Boundary_simplex_range;
/** \brief Returns a range giving access to all simplices of the
* boundary of a simplex, i.e.
* the set of codimension 1 subsimplices of the Simplex.
*
* If the simplex is \f$[v_0, \cdots ,v_d]\f$, with canonical orientation
* induced by \f$ v_0 < \cdots < v_d \f$, the iterator enumerates the
* simplices of the boundary in the order:
* \f$[v_0,\cdots,\widehat{v_i},\cdots,v_d]\f$ for \f$i\f$ from 0 to d
*
* We note that the alternate sum of the simplices given by the iterator
* gives the chains corresponding to the boundary of the simplex.*/
Boundary_simplex_range boundary_simplex_range(Simplex_handle sh);
/** \brief Iterator over all simplices of the complex
* in the order of the indexing scheme.
*
* 'value_type' must be 'Simplex_handle'.
*/
typedef unspecified Filtration_simplex_iterator;
/** \brief Range over the simplices of the complex
* in the order of the filtration.
*
* .begin() and .end() return type Filtration_simplex_iterator.*/
typedef unspecified Filtration_simplex_range;
/** \brief Returns a range over the simplices of the complex
* in the order of the filtration.
*
* .begin() and .end() return type Filtration_simplex_iterator.*/
Filtration_simplex_range filtration_simplex_range();
/** \name Map interface
* Conceptually a `std::unordered_map`.
* @{ */
/** \brief Data stored for each simplex.
*
* Must be an integer type. */
typedef unspecified Simplex_key;
/** \brief Returns a constant dummy number that is either negative,
* or at least as large as `num_simplices()`. Suggested value: -1. */
Simplex_key null_key ();
/** \brief Returns the number stored for a simplex by `assign_key`.
*
* This is never called on null_simplex(). */
Simplex_key key ( Simplex_handle sh );
/** \brief Store a number for a simplex, which can later be retrieved with `key(sh)`.
*
* This is never called on null_simplex(). */
void assign_key(Simplex_handle sh, Simplex_key n);
/** @} */
/* \brief Iterator over the simplices of the complex,
* in an arbitrary order.
*
* 'value_type' must be 'Simplex_handle'.*/
//typedef unspecified Complex_simplex_iterator;
//typedef unspecified Complex_simplex_range;
/*
* Returns a range over all the simplices of a
* complex.
*/
//Complex_simplex_range complex_simplex_range();
/*************************************************/ /**
* @details Compares the filtration values of simplices s and t
*
* @return -1 if s comes before t in the filtration, +1
* if it comes later, and 0 if they come at the same time
*
* @note OPTIONAL
* @todo use an enum? Just a bool?
*/
//int is_before_in_filtration(Simplex_handle s, Simplex_handle t);
/*************************************************/
};