3 files changed, 129 insertions, 0 deletions
diff --git a/src/Tangential_complex/example/CMakeLists.txt b/src/Tangential_complex/example/CMakeLists.txt
new file mode 100644
index 00000000..7ba043f0
--- /dev/null
+++ b/src/Tangential_complex/example/CMakeLists.txt
@@ -0,0 +1,30 @@
+cmake_minimum_required(VERSION 2.6)
+project(Tangential_complex_examples)
+
+if(CGAL_FOUND)
+  if (NOT CGAL_VERSION VERSION_LESS 4.8.0)
+    message(STATUS "CGAL version: ${CGAL_VERSION}.")
+
+    find_package(Eigen3 3.1.0)
+    if (EIGEN3_FOUND)
+      message(STATUS "Eigen3 version: ${EIGEN3_VERSION}.")
+      include( ${EIGEN3_USE_FILE} )
+      include_directories (BEFORE "../../include")
+
+      add_executable( Tangential_complex_example_basic example_basic.cpp )
+      target_link_libraries(Tangential_complex_example_basic ${CGAL_LIBRARY} ${Boost_DATE_TIME_LIBRARY})
+      add_executable( Tangential_complex_example_with_perturb example_with_perturb.cpp )
+      target_link_libraries(Tangential_complex_example_with_perturb ${CGAL_LIBRARY} ${Boost_DATE_TIME_LIBRARY})
+      if (TBB_FOUND)
+        target_link_libraries(Tangential_complex_example_basic ${TBB_LIBRARIES})
+        target_link_libraries(Tangential_complex_example_with_perturb ${TBB_LIBRARIES})
+      endif()
+    else()
+      message(WARNING "Eigen3 not found. Version 3.1.0 is required for the Tangential_complex examples.")
+    endif()
+  else()
+    message(WARNING "CGAL version: ${CGAL_VERSION} is too old to compile Tangential_complex examples. Version 4.8.0 is required.")
+  endif ()
+else()
+  message(WARNING "CGAL not found. It is required for the Tangential_complex examples.")
+endif()
diff --git a/src/Tangential_complex/example/example_basic.cpp b/src/Tangential_complex/example/example_basic.cpp
new file mode 100644
index 00000000..4f2b859e
--- /dev/null
+++ b/src/Tangential_complex/example/example_basic.cpp
@@ -0,0 +1,46 @@
+#include <gudhi/Tangential_complex.h>
+#include <gudhi/sparsify_point_set.h>
+
+#include <CGAL/Epick_d.h>
+#include <CGAL/Random.h>
+
+#include <array>
+#include <vector>
+
+namespace tc = Gudhi::tangential_complex;
+
+typedef CGAL::Epick_d<CGAL::Dynamic_dimension_tag> Kernel;
+typedef Kernel::FT FT;
+typedef Kernel::Point_d Point;
+typedef Kernel::Vector_d Vector;
+typedef tc::Tangential_complex<
+Kernel, CGAL::Dynamic_dimension_tag,
+CGAL::Parallel_tag> TC;
+
+int main(void) {
+  const int INTRINSIC_DIM = 2;
+  const int AMBIENT_DIM = 3;
+  const int NUM_POINTS = 1000;
+
+  Kernel k;
+
+  // Generate points on a 2-sphere
+  CGAL::Random_points_on_sphere_d<Point> generator(AMBIENT_DIM, 3.);
+  std::vector<Point> points;
+  points.reserve(NUM_POINTS);
+  for (int i = 0; i < NUM_POINTS; ++i)
+    points.push_back(*generator++);
+
+  // Compute the TC
+  TC tc(points, INTRINSIC_DIM, k);
+  tc.compute_tangential_complex();
+
+  // Export the TC into a Simplex_tree
+  Gudhi::Simplex_tree<> stree;
+  tc.create_complex(stree);
+
+  // Display stats about inconsistencies
+  tc.number_of_inconsistent_simplices(true);  // verbose
+
+  return 0;
+}
diff --git a/src/Tangential_complex/example/example_with_perturb.cpp b/src/Tangential_complex/example/example_with_perturb.cpp
new file mode 100644
index 00000000..d0d877ea
--- /dev/null
+++ b/src/Tangential_complex/example/example_with_perturb.cpp
@@ -0,0 +1,53 @@
+#include <gudhi/Tangential_complex.h>
+#include <gudhi/sparsify_point_set.h>
+
+#include <CGAL/Epick_d.h>
+#include <CGAL/Random.h>
+
+#include <array>
+#include <vector>
+
+namespace subsampl = Gudhi::subsampling;
+namespace tc = Gudhi::tangential_complex;
+
+typedef CGAL::Epick_d<CGAL::Dimension_tag < 3 >> Kernel;
+typedef Kernel::FT FT;
+typedef Kernel::Point_d Point;
+typedef Kernel::Vector_d Vector;
+typedef tc::Tangential_complex<
+Kernel, CGAL::Dimension_tag<2>,
+CGAL::Parallel_tag> TC;
+
+int main(void) {
+  const int INTRINSIC_DIM = 2;
+  const int AMBIENT_DIM = 3;
+  const int NUM_POINTS = 50;
+
+  Kernel k;
+
+  // Generate points on a 2-sphere
+  CGAL::Random_points_on_sphere_d<Point> generator(AMBIENT_DIM, 3.);
+  std::vector<Point> points;
+  points.reserve(NUM_POINTS);
+  for (int i = 0; i < NUM_POINTS; ++i)
+    points.push_back(*generator++);
+
+  // Sparsify the point set
+  std::vector<Point> sparsified_points;
+  subsampl::sparsify_point_set(k, points, 0.1 * 0.1,
+                               std::back_inserter(sparsified_points));
+  sparsified_points.swap(points);
+
+  // Compute the TC
+  TC tc(points, INTRINSIC_DIM, k);
+  tc.compute_tangential_complex();
+
+  // Try to fix inconsistencies. Give it 10 seconds to succeed
+  tc.fix_inconsistencies_using_perturbation(0.05, 10);
+
+  // Export the TC into a Simplex_tree
+  Gudhi::Simplex_tree<> stree;
+  tc.create_complex(stree);
+
+  return 0;
+}