Merge remote-tracking branch 'upstream/master' into persistence_graphical_tools_improvements

4 files changed, 36 insertions, 6 deletions

diff --git a/src/Alpha_complex/doc/Intro_alpha_complex.h b/src/Alpha_complex/doc/Intro_alpha_complex.h
index f417ebb2..5ab23720 100644
--- a/src/Alpha_complex/doc/Intro_alpha_complex.h
+++ b/src/Alpha_complex/doc/Intro_alpha_complex.h
@@ -152,6 +152,8 @@ Table of Contents
  * not quite define a proper filtration (i.e. non-decreasing with respect to inclusion).
  * We fix that up by calling `SimplicialComplexForAlpha::make_filtration_non_decreasing()`.
  *
+ * \note This is not the case in `exact` version, this is the reason why it is not called in this case.
+ *
  * \subsubsection pruneabove Prune above given filtration value
  *
  * The simplex tree is pruned from the given maximum \f$ \alpha^2 \f$ value (cf.
diff --git a/src/Alpha_complex/include/gudhi/Alpha_complex.h b/src/Alpha_complex/include/gudhi/Alpha_complex.h
index b315fa99..028ec9bb 100644
--- a/src/Alpha_complex/include/gudhi/Alpha_complex.h
+++ b/src/Alpha_complex/include/gudhi/Alpha_complex.h
@@ -20,6 +20,7 @@
 #include <stdlib.h>
 #include <math.h>  // isnan, fmax
 #include <memory>  // for std::unique_ptr
+#include <cstddef>  // for std::size_t
 
 #include <CGAL/Delaunay_triangulation.h>
 #include <CGAL/Regular_triangulation.h>  // aka. Weighted Delaunay triangulation
@@ -213,6 +214,15 @@ class Alpha_complex {
   Alpha_complex (Alpha_complex&& other) = delete;
   Alpha_complex& operator= (Alpha_complex&& other) = delete;
 
+  /** \brief Returns the number of finite vertices in the triangulation.
+   */
+  std::size_t num_vertices() const {
+    if (triangulation_ == nullptr)
+      return 0;
+    else
+      return triangulation_->number_of_vertices();
+  }
+
   /** \brief get_point returns the point corresponding to the vertex given as parameter.
    *
    * @param[in] vertex Vertex handle of the point to retrieve.
@@ -373,7 +383,7 @@ class Alpha_complex {
 
     // --------------------------------------------------------------------------------------------
     // Simplex_tree construction from loop on triangulation finite full cells list
-    if (triangulation_->number_of_vertices() > 0) {
+    if (num_vertices() > 0) {
       for (auto cit = triangulation_->finite_full_cells_begin();
            cit != triangulation_->finite_full_cells_end();
            ++cit) {
@@ -435,8 +445,10 @@ class Alpha_complex {
       // --------------------------------------------------------------------------------------------
   
       // --------------------------------------------------------------------------------------------
-      // As Alpha value is an approximation, we have to make filtration non decreasing while increasing the dimension
-      complex.make_filtration_non_decreasing();
+      if (!exact)
+        // As Alpha value is an approximation, we have to make filtration non decreasing while increasing the dimension
+        // Only in not exact version, cf. https://github.com/GUDHI/gudhi-devel/issues/57
+        complex.make_filtration_non_decreasing();
       // Remove all simplices that have a filtration value greater than max_alpha_square
       complex.prune_above_filtration(max_alpha_square);
       // --------------------------------------------------------------------------------------------
diff --git a/src/Alpha_complex/include/gudhi/Alpha_complex_3d.h b/src/Alpha_complex/include/gudhi/Alpha_complex_3d.h
index 4e5fc933..df5c630e 100644
--- a/src/Alpha_complex/include/gudhi/Alpha_complex_3d.h
+++ b/src/Alpha_complex/include/gudhi/Alpha_complex_3d.h
@@ -12,7 +12,6 @@
 #ifndef ALPHA_COMPLEX_3D_H_
 #define ALPHA_COMPLEX_3D_H_
 
-#include <boost/version.hpp>
 #include <boost/variant.hpp>
 #include <boost/range/size.hpp>
 #include <boost/range/combine.hpp>
@@ -554,8 +553,10 @@ Weighted_alpha_complex_3d::Weighted_point_3 wp0(Weighted_alpha_complex_3d::Bare_
     std::clog << "cells \t\t" << count_cells << std::endl;
 #endif  // DEBUG_TRACES
     // --------------------------------------------------------------------------------------------
-    // As Alpha value is an approximation, we have to make filtration non decreasing while increasing the dimension
-    complex.make_filtration_non_decreasing();
+    if (Complexity == complexity::FAST)
+      // As Alpha value is an approximation, we have to make filtration non decreasing while increasing the dimension
+      // Only in FAST version, cf. https://github.com/GUDHI/gudhi-devel/issues/57
+      complex.make_filtration_non_decreasing();
     // Remove all simplices that have a filtration value greater than max_alpha_square
     complex.prune_above_filtration(max_alpha_square);
     // --------------------------------------------------------------------------------------------
diff --git a/src/Alpha_complex/test/Alpha_complex_unit_test.cpp b/src/Alpha_complex/test/Alpha_complex_unit_test.cpp
index 4b37e4bd..f74ad217 100644
--- a/src/Alpha_complex/test/Alpha_complex_unit_test.cpp
+++ b/src/Alpha_complex/test/Alpha_complex_unit_test.cpp
@@ -56,6 +56,9 @@ BOOST_AUTO_TEST_CASE_TEMPLATE(Alpha_complex_from_OFF_file, TestedKernel, list_of
   Gudhi::Simplex_tree<> simplex_tree_60;
   BOOST_CHECK(alpha_complex_from_file.create_complex(simplex_tree_60, max_alpha_square_value));
 
+  std::clog << "alpha_complex_from_file.num_vertices()=" << alpha_complex_from_file.num_vertices() << std::endl;
+  BOOST_CHECK(alpha_complex_from_file.num_vertices() == 7);
+
   std::clog << "simplex_tree_60.dimension()=" << simplex_tree_60.dimension() << std::endl;
   BOOST_CHECK(simplex_tree_60.dimension() == 2);
 
@@ -72,6 +75,9 @@ BOOST_AUTO_TEST_CASE_TEMPLATE(Alpha_complex_from_OFF_file, TestedKernel, list_of
   Gudhi::Simplex_tree<> simplex_tree_59;
   BOOST_CHECK(alpha_complex_from_file.create_complex(simplex_tree_59, max_alpha_square_value));
   
+  std::clog << "alpha_complex_from_file.num_vertices()=" << alpha_complex_from_file.num_vertices() << std::endl;
+  BOOST_CHECK(alpha_complex_from_file.num_vertices() == 7);
+
   std::clog << "simplex_tree_59.dimension()=" << simplex_tree_59.dimension() << std::endl;
   BOOST_CHECK(simplex_tree_59.dimension() == 2);
 
@@ -120,6 +126,9 @@ BOOST_AUTO_TEST_CASE(Alpha_complex_from_points) {
   Gudhi::Simplex_tree<> simplex_tree;
   BOOST_CHECK(alpha_complex_from_points.create_complex(simplex_tree));
   
+  std::clog << "alpha_complex_from_points.num_vertices()=" << alpha_complex_from_points.num_vertices() << std::endl;
+  BOOST_CHECK(alpha_complex_from_points.num_vertices() == points.size());
+
   // Another way to check num_simplices
   std::clog << "Iterator on alpha complex simplices in the filtration order, with [filtration value]:" << std::endl;
   int num_simplices = 0;
@@ -240,6 +249,9 @@ BOOST_AUTO_TEST_CASE_TEMPLATE(Alpha_complex_from_empty_points, TestedKernel, lis
   // ----------------------------------------------------------------------------
   Gudhi::alpha_complex::Alpha_complex<TestedKernel> alpha_complex_from_points(points);
 
+  std::clog << "alpha_complex_from_points.num_vertices()=" << alpha_complex_from_points.num_vertices() << std::endl;
+  BOOST_CHECK(alpha_complex_from_points.num_vertices() == points.size());
+
   // Test to the limit
   BOOST_CHECK_THROW (alpha_complex_from_points.get_point(0), std::out_of_range);
 
@@ -291,6 +303,9 @@ BOOST_AUTO_TEST_CASE_TEMPLATE(Alpha_complex_with_duplicated_points, TestedKernel
   std::clog << "create_complex" << std::endl;
   BOOST_CHECK(alpha_complex_from_points.create_complex(simplex_tree));
   
+  std::clog << "alpha_complex_from_points.num_vertices()=" << alpha_complex_from_points.num_vertices() << std::endl;
+  BOOST_CHECK(alpha_complex_from_points.num_vertices() < points.size());
+
   std::clog << "simplex_tree.num_vertices()=" << simplex_tree.num_vertices()
       << std::endl;
   BOOST_CHECK(simplex_tree.num_vertices() < points.size());