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authorHind-M <hind.montassif@gmail.com>2022-04-25 14:57:26 +0200
committerHind-M <hind.montassif@gmail.com>2022-04-25 14:57:26 +0200
commit8730db2e8d1a8663358168ff6a20881c97773002 (patch)
tree24d3603e752fcb6a6b99978ed0ffcb7d5436714e /src/Cech_complex/include
parentdbb65c3f3eb82d080e47b40b52deb03814d8da31 (diff)
Remove cech_complex_step_by_step example and Miniball
Diffstat (limited to 'src/Cech_complex/include')
-rw-r--r--src/Cech_complex/include/gudhi/Miniball.COPYRIGHT4
-rw-r--r--src/Cech_complex/include/gudhi/Miniball.README26
-rw-r--r--src/Cech_complex/include/gudhi/Miniball.hpp523
3 files changed, 0 insertions, 553 deletions
diff --git a/src/Cech_complex/include/gudhi/Miniball.COPYRIGHT b/src/Cech_complex/include/gudhi/Miniball.COPYRIGHT
deleted file mode 100644
index dbe4c553..00000000
--- a/src/Cech_complex/include/gudhi/Miniball.COPYRIGHT
+++ /dev/null
@@ -1,4 +0,0 @@
-The miniball software is available under the GNU General Public License (GPLv3 - https://www.gnu.org/copyleft/gpl.html).
-If your intended use is not compliant with this license, please buy a commercial license (EUR 500 - https://people.inf.ethz.ch/gaertner/subdir/software/miniball/license.html).
-You need a license if the software that you develop using Miniball V3.0 is not open source.
-
diff --git a/src/Cech_complex/include/gudhi/Miniball.README b/src/Cech_complex/include/gudhi/Miniball.README
deleted file mode 100644
index 033d8953..00000000
--- a/src/Cech_complex/include/gudhi/Miniball.README
+++ /dev/null
@@ -1,26 +0,0 @@
-https://people.inf.ethz.ch/gaertner/subdir/software/miniball.html
-
-Smallest Enclosing Balls of Points - Fast and Robust in C++.
-(high-quality software for smallest enclosing balls of balls is available in the computational geometry algorithms library CGAL)
-
-
-This is the miniball software (V3.0) for computing smallest enclosing balls of points in arbitrary dimensions. It consists of a C++ header file Miniball.hpp (around 500 lines of code) and two example programs miniball_example.cpp and miniball_example_containers.cpp that demonstrate the usage. The first example stores the coordinates of the input points in a two-dimensional array, the second example uses a list of vectors to show how generic containers can be used.
-
-Credits: Aditya Gupta and Alexandros Konstantinakis-Karmis have significantly contributed to this version of the software.
-
-Changes - https://people.inf.ethz.ch/gaertner/subdir/software/miniball/changes.txt - from previous versions.
-
-The theory - https://people.inf.ethz.ch/gaertner/subdir/texts/own_work/esa99_final.pdf - behind the miniball software (Proc. 7th Annual European Symposium on Algorithms (ESA), Lecture Notes in Computer Science 1643, Springer-Verlag, pp.325-338, 1999).
-
-Main Features:
-
- Very fast in low dimensions. 1 million points in 5-space are processed within 0.05 seconds on any recent machine.
-
- High numerical stability. Almost all input degeneracies (cospherical points, multiple points, points very close together) are routinely handled.
-
- Easily integrates into your code. You can freely choose the coordinate type of your points and the container to store the points. If you still need to adapt the code, the header is small and readable and contains documentation for all major methods.
-
-
-Changes done for the GUDHI version of MiniBall:
- - Add include guard
- - Move Miniball namespace inside a new Gudhi namespace
diff --git a/src/Cech_complex/include/gudhi/Miniball.hpp b/src/Cech_complex/include/gudhi/Miniball.hpp
deleted file mode 100644
index ce6cbb5b..00000000
--- a/src/Cech_complex/include/gudhi/Miniball.hpp
+++ /dev/null
@@ -1,523 +0,0 @@
-// Copright (C) 1999-2013, Bernd Gaertner
-// $Rev: 3581 $
-//
-// 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/>.
-//
-// Contact:
-// --------
-// Bernd Gaertner
-// Institute of Theoretical Computer Science
-// ETH Zuerich
-// CAB G31.1
-// CH-8092 Zuerich, Switzerland
-// http://www.inf.ethz.ch/personal/gaertner
-
-#ifndef MINIBALL_HPP_
-#define MINIBALL_HPP_
-
-#include <cassert>
-#include <algorithm>
-#include <list>
-#include <ctime>
-#include <limits>
-
-namespace Gudhi {
-
-namespace Miniball {
-
- // Global Functions
- // ================
- template <typename NT>
- inline NT mb_sqr (NT r) {return r*r;}
-
- // Functors
- // ========
-
- // functor to map a point iterator to the corresponding coordinate iterator;
- // generic version for points whose coordinate containers have begin()
- template < typename Pit_, typename Cit_ >
- struct CoordAccessor {
- typedef Pit_ Pit;
- typedef Cit_ Cit;
- inline Cit operator() (Pit it) const { return (*it).begin(); }
- };
-
- // partial specialization for points whose coordinate containers are arrays
- template < typename Pit_, typename Cit_ >
- struct CoordAccessor<Pit_, Cit_*> {
- typedef Pit_ Pit;
- typedef Cit_* Cit;
- inline Cit operator() (Pit it) const { return *it; }
- };
-
- // Class Declaration
- // =================
-
- template <typename CoordAccessor>
- class Miniball {
- private:
- // types
- // The iterator type to go through the input points
- typedef typename CoordAccessor::Pit Pit;
- // The iterator type to go through the coordinates of a single point.
- typedef typename CoordAccessor::Cit Cit;
- // The coordinate type
- typedef typename std::iterator_traits<Cit>::value_type NT;
- // The iterator to go through the support points
- typedef typename std::list<Pit>::iterator Sit;
-
- // data members...
- const int d; // dimension
- Pit points_begin;
- Pit points_end;
- CoordAccessor coord_accessor;
- double time;
- const NT nt0; // NT(0)
-
- //...for the algorithms
- std::list<Pit> L;
- Sit support_end;
- int fsize; // number of forced points
- int ssize; // number of support points
-
- // ...for the ball updates
- NT* current_c;
- NT current_sqr_r;
- NT** c;
- NT* sqr_r;
-
- // helper arrays
- NT* q0;
- NT* z;
- NT* f;
- NT** v;
- NT** a;
-
- public:
- // The iterator type to go through the support points
- typedef typename std::list<Pit>::const_iterator SupportPointIterator;
-
- // PRE: [begin, end) is a nonempty range
- // POST: computes the smallest enclosing ball of the points in the range
- // [begin, end); the functor a maps a point iterator to an iterator
- // through the d coordinates of the point
- Miniball (int d_, Pit begin, Pit end, CoordAccessor ca = CoordAccessor());
-
- // POST: returns a pointer to the first element of an array that holds
- // the d coordinates of the center of the computed ball
- const NT* center () const;
-
- // POST: returns the squared radius of the computed ball
- NT squared_radius () const;
-
- // POST: returns the number of support points of the computed ball;
- // the support points form a minimal set with the same smallest
- // enclosing ball as the input set; in particular, the support
- // points are on the boundary of the computed ball, and their
- // number is at most d+1
- int nr_support_points () const;
-
- // POST: returns an iterator to the first support point
- SupportPointIterator support_points_begin () const;
-
- // POST: returns a past-the-end iterator for the range of support points
- SupportPointIterator support_points_end () const;
-
- // POST: returns the maximum excess of any input point w.r.t. the computed
- // ball, divided by the squared radius of the computed ball. The
- // excess of a point is the difference between its squared distance
- // from the center and the squared radius; Ideally, the return value
- // is 0. subopt is set to the absolute value of the most negative
- // coefficient in the affine combination of the support points that
- // yields the center. Ideally, this is a convex combination, and there
- // is no negative coefficient in which case subopt is set to 0.
- NT relative_error (NT& subopt) const;
-
- // POST: return true if the relative error is at most tol, and the
- // suboptimality is 0; the default tolerance is 10 times the
- // coordinate type's machine epsilon
- bool is_valid (NT tol = NT(10) * std::numeric_limits<NT>::epsilon()) const;
-
- // POST: returns the time in seconds taken by the constructor call for
- // computing the smallest enclosing ball
- double get_time() const;
-
- // POST: deletes dynamically allocated arrays
- ~Miniball();
-
- private:
- void mtf_mb (Sit n);
- void mtf_move_to_front (Sit j);
- void pivot_mb (Pit n);
- void pivot_move_to_front (Pit j);
- NT excess (Pit pit) const;
- void pop ();
- bool push (Pit pit);
- NT suboptimality () const;
- void create_arrays();
- void delete_arrays();
- };
-
- // Class Definition
- // ================
- template <typename CoordAccessor>
- Miniball<CoordAccessor>::Miniball (int d_, Pit begin, Pit end,
- CoordAccessor ca)
- : d (d_),
- points_begin (begin),
- points_end (end),
- coord_accessor (ca),
- time (clock()),
- nt0 (NT(0)),
- L(),
- support_end (L.begin()),
- fsize(0),
- ssize(0),
- current_c (NULL),
- current_sqr_r (NT(-1)),
- c (NULL),
- sqr_r (NULL),
- q0 (NULL),
- z (NULL),
- f (NULL),
- v (NULL),
- a (NULL)
- {
- assert (points_begin != points_end);
- create_arrays();
-
- // set initial center
- for (int j=0; j<d; ++j) c[0][j] = nt0;
- current_c = c[0];
-
- // compute miniball
- pivot_mb (points_end);
-
- // update time
- time = (clock() - time) / CLOCKS_PER_SEC;
- }
-
- template <typename CoordAccessor>
- Miniball<CoordAccessor>::~Miniball()
- {
- delete_arrays();
- }
-
- template <typename CoordAccessor>
- void Miniball<CoordAccessor>::create_arrays()
- {
- c = new NT*[d+1];
- v = new NT*[d+1];
- a = new NT*[d+1];
- for (int i=0; i<d+1; ++i) {
- c[i] = new NT[d];
- v[i] = new NT[d];
- a[i] = new NT[d];
- }
- sqr_r = new NT[d+1];
- q0 = new NT[d];
- z = new NT[d+1];
- f = new NT[d+1];
- }
-
- template <typename CoordAccessor>
- void Miniball<CoordAccessor>::delete_arrays()
- {
- delete[] f;
- delete[] z;
- delete[] q0;
- delete[] sqr_r;
- for (int i=0; i<d+1; ++i) {
- delete[] a[i];
- delete[] v[i];
- delete[] c[i];
- }
- delete[] a;
- delete[] v;
- delete[] c;
- }
-
- template <typename CoordAccessor>
- const typename Miniball<CoordAccessor>::NT*
- Miniball<CoordAccessor>::center () const
- {
- return current_c;
- }
-
- template <typename CoordAccessor>
- typename Miniball<CoordAccessor>::NT
- Miniball<CoordAccessor>::squared_radius () const
- {
- return current_sqr_r;
- }
-
- template <typename CoordAccessor>
- int Miniball<CoordAccessor>::nr_support_points () const
- {
- assert (ssize < d+2);
- return ssize;
- }
-
- template <typename CoordAccessor>
- typename Miniball<CoordAccessor>::SupportPointIterator
- Miniball<CoordAccessor>::support_points_begin () const
- {
- return L.begin();
- }
-
- template <typename CoordAccessor>
- typename Miniball<CoordAccessor>::SupportPointIterator
- Miniball<CoordAccessor>::support_points_end () const
- {
- return support_end;
- }
-
- template <typename CoordAccessor>
- typename Miniball<CoordAccessor>::NT
- Miniball<CoordAccessor>::relative_error (NT& subopt) const
- {
- NT e, max_e = nt0;
- // compute maximum absolute excess of support points
- for (SupportPointIterator it = support_points_begin();
- it != support_points_end(); ++it) {
- e = excess (*it);
- if (e < nt0) e = -e;
- if (e > max_e) {
- max_e = e;
- }
- }
- // compute maximum excess of any point
- for (Pit i = points_begin; i != points_end; ++i)
- if ((e = excess (i)) > max_e)
- max_e = e;
-
- subopt = suboptimality();
- assert (current_sqr_r > nt0 || max_e == nt0);
- return (current_sqr_r == nt0 ? nt0 : max_e / current_sqr_r);
- }
-
- template <typename CoordAccessor>
- bool Miniball<CoordAccessor>::is_valid (NT tol) const
- {
- NT suboptimality;
- return ( (relative_error (suboptimality) <= tol) && (suboptimality == 0) );
- }
-
- template <typename CoordAccessor>
- double Miniball<CoordAccessor>::get_time() const
- {
- return time;
- }
-
- template <typename CoordAccessor>
- void Miniball<CoordAccessor>::mtf_mb (Sit n)
- {
- // Algorithm 1: mtf_mb (L_{n-1}, B), where L_{n-1} = [L.begin, n)
- // B: the set of forced points, defining the current ball
- // S: the superset of support points computed by the algorithm
- // --------------------------------------------------------------
- // from B. Gaertner, Fast and Robust Smallest Enclosing Balls, ESA 1999,
- // http://www.inf.ethz.ch/personal/gaertner/texts/own_work/esa99_final.pdf
-
- // PRE: B = S
- assert (fsize == ssize);
-
- support_end = L.begin();
- if ((fsize) == d+1) return;
-
- // incremental construction
- for (Sit i = L.begin(); i != n;)
- {
- // INV: (support_end - L.begin() == |S|-|B|)
- assert (std::distance (L.begin(), support_end) == ssize - fsize);
-
- Sit j = i++;
- if (excess(*j) > nt0)
- if (push(*j)) { // B := B + p_i
- mtf_mb (j); // mtf_mb (L_{i-1}, B + p_i)
- pop(); // B := B - p_i
- mtf_move_to_front(j);
- }
- }
- // POST: the range [L.begin(), support_end) stores the set S\B
- }
-
- template <typename CoordAccessor>
- void Miniball<CoordAccessor>::mtf_move_to_front (Sit j)
- {
- if (support_end == j)
- support_end++;
- L.splice (L.begin(), L, j);
- }
-
- template <typename CoordAccessor>
- void Miniball<CoordAccessor>::pivot_mb (Pit n)
- {
- // Algorithm 2: pivot_mb (L_{n-1}), where L_{n-1} = [L.begin, n)
- // --------------------------------------------------------------
- // from B. Gaertner, Fast and Robust Smallest Enclosing Balls, ESA 1999,
- // http://www.inf.ethz.ch/personal/gaertner/texts/own_work/esa99_final.pdf
- NT old_sqr_r;
- const NT* c;
- Pit pivot, k;
- NT e, max_e, sqr_r;
- Cit p;
- do {
- old_sqr_r = current_sqr_r;
- sqr_r = current_sqr_r;
-
- pivot = points_begin;
- max_e = nt0;
- for (k = points_begin; k != n; ++k) {
- p = coord_accessor(k);
- e = -sqr_r;
- c = current_c;
- for (int j=0; j<d; ++j)
- e += mb_sqr<NT>(*p++-*c++);
- if (e > max_e) {
- max_e = e;
- pivot = k;
- }
- }
-
- if (max_e > nt0) {
- // check if the pivot is already contained in the support set
- if (std::find(L.begin(), support_end, pivot) == support_end) {
- assert (fsize == 0);
- if (push (pivot)) {
- mtf_mb(support_end);
- pop();
- pivot_move_to_front(pivot);
- }
- }
- }
- } while (old_sqr_r < current_sqr_r);
- }
-
- template <typename CoordAccessor>
- void Miniball<CoordAccessor>::pivot_move_to_front (Pit j)
- {
- L.push_front(j);
- if (std::distance(L.begin(), support_end) == d+2)
- support_end--;
- }
-
- template <typename CoordAccessor>
- inline typename Miniball<CoordAccessor>::NT
- Miniball<CoordAccessor>::excess (Pit pit) const
- {
- Cit p = coord_accessor(pit);
- NT e = -current_sqr_r;
- NT* c = current_c;
- for (int k=0; k<d; ++k){
- e += mb_sqr<NT>(*p++-*c++);
- }
- return e;
- }
-
- template <typename CoordAccessor>
- void Miniball<CoordAccessor>::pop ()
- {
- --fsize;
- }
-
- template <typename CoordAccessor>
- bool Miniball<CoordAccessor>::push (Pit pit)
- {
- int i, j;
- NT eps = mb_sqr<NT>(std::numeric_limits<NT>::epsilon());
-
- Cit cit = coord_accessor(pit);
- Cit p = cit;
-
- if (fsize==0) {
- for (i=0; i<d; ++i)
- q0[i] = *p++;
- for (i=0; i<d; ++i)
- c[0][i] = q0[i];
- sqr_r[0] = nt0;
- }
- else {
- // set v_fsize to Q_fsize
- for (i=0; i<d; ++i)
- //v[fsize][i] = p[i]-q0[i];
- v[fsize][i] = *p++-q0[i];
-
- // compute the a_{fsize,i}, i< fsize
- for (i=1; i<fsize; ++i) {
- a[fsize][i] = nt0;
- for (j=0; j<d; ++j)
- a[fsize][i] += v[i][j] * v[fsize][j];
- a[fsize][i]*=(2/z[i]);
- }
-
- // update v_fsize to Q_fsize-\bar{Q}_fsize
- for (i=1; i<fsize; ++i) {
- for (j=0; j<d; ++j)
- v[fsize][j] -= a[fsize][i]*v[i][j];
- }
-
- // compute z_fsize
- z[fsize]=nt0;
- for (j=0; j<d; ++j)
- z[fsize] += mb_sqr<NT>(v[fsize][j]);
- z[fsize]*=2;
-
- // reject push if z_fsize too small
- if (z[fsize]<eps*current_sqr_r) {
- return false;
- }
-
- // update c, sqr_r
- p=cit;
- NT e = -sqr_r[fsize-1];
- for (i=0; i<d; ++i)
- e += mb_sqr<NT>(*p++-c[fsize-1][i]);
- f[fsize]=e/z[fsize];
-
- for (i=0; i<d; ++i)
- c[fsize][i] = c[fsize-1][i]+f[fsize]*v[fsize][i];
- sqr_r[fsize] = sqr_r[fsize-1] + e*f[fsize]/2;
- }
- current_c = c[fsize];
- current_sqr_r = sqr_r[fsize];
- ssize = ++fsize;
- return true;
- }
-
- template <typename CoordAccessor>
- typename Miniball<CoordAccessor>::NT
- Miniball<CoordAccessor>::suboptimality () const
- {
- NT* l = new NT[d+1];
- NT min_l = nt0;
- l[0] = NT(1);
- for (int i=ssize-1; i>0; --i) {
- l[i] = f[i];
- for (int k=ssize-1; k>i; --k)
- l[i]-=a[k][i]*l[k];
- if (l[i] < min_l) min_l = l[i];
- l[0] -= l[i];
- }
- if (l[0] < min_l) min_l = l[0];
- delete[] l;
- if (min_l < nt0)
- return -min_l;
- return nt0;
- }
-} // namespace Miniball
-
-} // namespace Gudhi
-
-#endif // MINIBALL_HPP_