Merge last trunk modificat

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/rips_complex_from_correlation_matrix@3212 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: ea6296547b67ad82f5983d4309493e9131da7dd0

4 files changed, 130 insertions, 9 deletions

diff --git a/src/common/include/gudhi/Debug_utils.h b/src/common/include/gudhi/Debug_utils.h
index 8ed3b7b3..90d3cf47 100644
--- a/src/common/include/gudhi/Debug_utils.h
+++ b/src/common/include/gudhi/Debug_utils.h
@@ -4,7 +4,7 @@
  *
  *    Author(s):       David Salinas
  *
- *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *    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
@@ -32,7 +32,7 @@
 // GUDHI_CHECK throw an exception if expression is false in debug mode, but does nothing in release mode
 // Could assert in release mode, but cmake sets NDEBUG (for "NO DEBUG") in this mode, means assert does nothing.
 #ifdef GUDHI_DEBUG
-  #define GUDHI_CHECK(expression, excpt) if ((expression) == 0) throw excpt
+  #define GUDHI_CHECK(expression, excpt) ((expression) ? (void) 0 : (throw excpt))
   #define GUDHI_CHECK_code(CODE) CODE
 #else
   #define GUDHI_CHECK(expression, excpt) (void) 0
diff --git a/src/common/include/gudhi/Unitary_tests_utils.h b/src/common/include/gudhi/Unitary_tests_utils.h
new file mode 100644
index 00000000..8394a062
--- /dev/null
+++ b/src/common/include/gudhi/Unitary_tests_utils.h
@@ -0,0 +1,40 @@
+/*    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):       Vincent Rouvreau
+ *
+ *    Copyright (C) 2017  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 <http://www.gnu.org/licenses/>.
+ */
+#ifndef UNITARY_TESTS_UTILS_H_
+#define UNITARY_TESTS_UTILS_H_
+
+#include <boost/test/unit_test.hpp>
+
+#include <iostream>
+#include <limits>  // for std::numeric_limits<>
+
+template<typename FloatingType >
+void GUDHI_TEST_FLOAT_EQUALITY_CHECK(FloatingType a, FloatingType b,
+                                     FloatingType epsilon = std::numeric_limits<FloatingType>::epsilon()) {
+#ifdef DEBUG_TRACES
+  std::cout << "GUDHI_TEST_FLOAT_EQUALITY_CHECK - " << a << " versus " << b
+            << " | diff = " << std::fabs(a - b) << " - epsilon = " << epsilon << std::endl;
+#endif
+  BOOST_CHECK(std::fabs(a - b) < epsilon);
+}
+
+#endif  // UNITARY_TESTS_UTILS_H_
diff --git a/src/common/include/gudhi/distance_functions.h b/src/common/include/gudhi/distance_functions.h
index f6e2ab5a..3a5d1fd5 100644
--- a/src/common/include/gudhi/distance_functions.h
+++ b/src/common/include/gudhi/distance_functions.h
@@ -23,9 +23,14 @@
 #ifndef DISTANCE_FUNCTIONS_H_
 #define DISTANCE_FUNCTIONS_H_
 
+#include <gudhi/Debug_utils.h>
+
+#include <boost/range/metafunctions.hpp>
+
 #include <cmath>  // for std::sqrt
 #include <type_traits>  // for std::decay
 #include <iterator>  // for std::begin, std::end
+#include <utility>
 
 namespace Gudhi {
 
@@ -37,16 +42,29 @@ namespace Gudhi {
  * have the same dimension. */
 class Euclidean_distance {
  public:
+  // boost::range_value is not SFINAE-friendly so we cannot use it in the return type
   template< typename Point >
-  auto operator()(const Point& p1, const Point& p2) const -> typename std::decay<decltype(*std::begin(p1))>::type {
-    auto it1 = p1.begin();
-    auto it2 = p2.begin();
-    typename Point::value_type dist = 0.;
-    for (; it1 != p1.end(); ++it1, ++it2) {
-      typename Point::value_type tmp = (*it1) - (*it2);
+  typename std::iterator_traits<typename boost::range_iterator<Point>::type>::value_type
+  operator()(const Point& p1, const Point& p2) const {
+    auto it1 = std::begin(p1);
+    auto it2 = std::begin(p2);
+    typedef typename boost::range_value<Point>::type NT;
+    NT dist = 0;
+    for (; it1 != std::end(p1); ++it1, ++it2) {
+      GUDHI_CHECK(it2 != std::end(p2), "inconsistent point dimensions");
+      NT tmp = *it1 - *it2;
       dist += tmp*tmp;
     }
-    return std::sqrt(dist);
+    GUDHI_CHECK(it2 == std::end(p2), "inconsistent point dimensions");
+    using std::sqrt;
+    return sqrt(dist);
+  }
+  template< typename T >
+  T operator() (const std::pair< T, T >& f, const std::pair< T, T >& s) const {
+    T dx = f.first - s.first;
+    T dy = f.second - s.second;
+    using std::sqrt;
+    return sqrt(dx*dx + dy*dy);
   }
 };
 
diff --git a/src/common/include/gudhi/graph_simplicial_complex.h b/src/common/include/gudhi/graph_simplicial_complex.h
index 5fe7c826..d84421b2 100644
--- a/src/common/include/gudhi/graph_simplicial_complex.h
+++ b/src/common/include/gudhi/graph_simplicial_complex.h
@@ -28,6 +28,9 @@
 #include <utility>  // for pair<>
 #include <vector>
 #include <map>
+#include <tuple>  // for std::tie
+
+namespace Gudhi {
 
 /* Edge tag for Boost PropertyGraph. */
 struct edge_filtration_t {
@@ -39,4 +42,64 @@ struct vertex_filtration_t {
   typedef boost::vertex_property_tag kind;
 };
 
+template <typename SimplicialComplexForProximityGraph>
+using Proximity_graph = typename boost::adjacency_list < boost::vecS, boost::vecS, boost::undirectedS
+, boost::property < vertex_filtration_t, typename SimplicialComplexForProximityGraph::Filtration_value >
+, boost::property < edge_filtration_t, typename SimplicialComplexForProximityGraph::Filtration_value >>;
+
+/** \brief Computes the proximity graph of the points.
+ *
+ * If points contains n elements, the proximity graph is the graph with n vertices, and an edge [u,v] iff the
+ * distance function between points u and v is smaller than threshold.
+ *
+ * \tparam ForwardPointRange furnishes `.begin()` and `.end()` methods.
+ *
+ * \tparam Distance furnishes `operator()(const Point& p1, const Point& p2)`, where
+ * `Point` is a point from the `ForwardPointRange`, and that returns a `Filtration_value`.
+ */
+template< typename SimplicialComplexForProximityGraph
+          , typename ForwardPointRange
+          , typename Distance >
+Proximity_graph<SimplicialComplexForProximityGraph> compute_proximity_graph(
+    const ForwardPointRange& points,
+    typename SimplicialComplexForProximityGraph::Filtration_value threshold,
+    Distance distance) {
+  using Vertex_handle = typename SimplicialComplexForProximityGraph::Vertex_handle;
+  using Filtration_value = typename SimplicialComplexForProximityGraph::Filtration_value;
+
+  std::vector<std::pair< Vertex_handle, Vertex_handle >> edges;
+  std::vector< Filtration_value > edges_fil;
+  std::map< Vertex_handle, Filtration_value > vertices;
+
+  Vertex_handle idx_u, idx_v;
+  Filtration_value fil;
+  idx_u = 0;
+  for (auto it_u = points.begin(); it_u != points.end(); ++it_u) {
+    idx_v = idx_u + 1;
+    for (auto it_v = it_u + 1; it_v != points.end(); ++it_v, ++idx_v) {
+      fil = distance(*it_u, *it_v);
+      if (fil <= threshold) {
+        edges.emplace_back(idx_u, idx_v);
+        edges_fil.push_back(fil);
+      }
+    }
+    ++idx_u;
+  }
+
+  // Points are labeled from 0 to idx_u-1
+  Proximity_graph<SimplicialComplexForProximityGraph> skel_graph(edges.begin(), edges.end(), edges_fil.begin(), idx_u);
+
+  auto vertex_prop = boost::get(vertex_filtration_t(), skel_graph);
+
+  typename boost::graph_traits<Proximity_graph<SimplicialComplexForProximityGraph>>::vertex_iterator vi, vi_end;
+  for (std::tie(vi, vi_end) = boost::vertices(skel_graph);
+       vi != vi_end; ++vi) {
+    boost::put(vertex_prop, *vi, 0.);
+  }
+
+  return skel_graph;
+}
+
+}  // namespace Gudhi
+
 #endif  // GRAPH_SIMPLICIAL_COMPLEX_H_