From 8c820ca8f9da625084f94dc9b80bb936f2c7aa8a Mon Sep 17 00:00:00 2001
From: vrouvrea <vrouvrea@636b058d-ea47-450e-bf9e-a15bfbe3eedb>
Date: Thu, 19 Mar 2015 12:19:22 +0000
Subject: Add of bottleneck functionnality

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/bottleneckDistance@492 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: 68ecf70a07641fea7106a17bbbf45404747834cc
---
 src/Bottleneck/include/gudhi/Neighbors_finder.h | 96 +++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 src/Bottleneck/include/gudhi/Neighbors_finder.h

(limited to 'src/Bottleneck/include/gudhi/Neighbors_finder.h')

diff --git a/src/Bottleneck/include/gudhi/Neighbors_finder.h b/src/Bottleneck/include/gudhi/Neighbors_finder.h
new file mode 100644
index 00000000..98256571
--- /dev/null
+++ b/src/Bottleneck/include/gudhi/Neighbors_finder.h
@@ -0,0 +1,96 @@
+/*    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):       Francois Godi
+ *
+ *    Copyright (C) 2015  INRIA Saclay (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 SRC_BOTTLENECK_INCLUDE_GUDHI_NEIGHBORS_FINDER_H_
+#define SRC_BOTTLENECK_INCLUDE_GUDHI_NEIGHBORS_FINDER_H_
+
+#include <unordered_set>
+#include <list>
+
+#include "gudhi/Planar_neighbors_finder.h"
+
+namespace Gudhi {
+
+namespace bottleneck {
+
+// Neighbors_finder is a data structure used to find if a query point from U has neighbors in V
+// in the persistence diagrams graph.
+// V's points have to be added manually using their index. A neighbor returned is automatically removed.
+
+class Neighbors_finder {
+ public:
+  Neighbors_finder(const Persistence_diagrams_graph& g, double r);
+  void add(int v_point_index);
+  int pull_near(int u_point_index);
+  std::list<int>* pull_all_near(int u_point_index);
+
+ private:
+  const Persistence_diagrams_graph& g;
+  const double r;
+  Planar_neighbors_finder planar_neighbors_f;
+  std::unordered_set<int> projections_f;
+};
+
+Neighbors_finder::Neighbors_finder(const Persistence_diagrams_graph& g, double r) :
+    g(g), r(r), planar_neighbors_f(g, r), projections_f() { }
+
+inline void Neighbors_finder::add(int v_point_index) {
+  if (g.on_the_v_diagonal(v_point_index))
+    projections_f.emplace(v_point_index);
+  else
+    planar_neighbors_f.add(v_point_index);
+}
+
+inline int Neighbors_finder::pull_near(int u_point_index) {
+  int v_challenger = g.corresponding_point_in_v(u_point_index);
+  if (planar_neighbors_f.contains(v_challenger) && g.distance(u_point_index, v_challenger) < r) {
+    planar_neighbors_f.remove(v_challenger);
+    return v_challenger;
+  }
+  if (g.on_the_u_diagonal(u_point_index)) {
+    auto it = projections_f.cbegin();
+    if (it != projections_f.cend()) {
+      int tmp = *it;
+      projections_f.erase(it);
+      return tmp;
+    }
+  } else {
+    return planar_neighbors_f.pull_near(u_point_index);
+  }
+  return null_point_index();
+}
+
+inline std::list<int>* Neighbors_finder::pull_all_near(int u_point_index) {
+  std::list<int>* all_pull = planar_neighbors_f.pull_all_near(u_point_index);
+  int last_pull = pull_near(u_point_index);
+  while (last_pull != null_point_index()) {
+    all_pull->emplace_back(last_pull);
+    last_pull = pull_near(u_point_index);
+  }
+  return all_pull;
+}
+
+}  // namespace bottleneck
+
+}  // namespace Gudhi
+
+#endif  // SRC_BOTTLENECK_INCLUDE_GUDHI_NEIGHBORS_FINDER_H_
-- 
cgit v1.2.3