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-rw-r--r--src/Spatial_searching/example/CMakeLists.txt2
-rw-r--r--src/Spatial_searching/test/CMakeLists.txt2
-rw-r--r--src/Subsampling/example/CMakeLists.txt1
-rw-r--r--src/Subsampling/example/example_custom_kernel.cpp69
-rw-r--r--src/Subsampling/include/gudhi/choose_n_farthest_points.h36
-rw-r--r--src/Subsampling/test/test_choose_n_farthest_points.cpp55
6 files changed, 106 insertions, 59 deletions
diff --git a/src/Spatial_searching/example/CMakeLists.txt b/src/Spatial_searching/example/CMakeLists.txt
index e73b201c..6238a0ec 100644
--- a/src/Spatial_searching/example/CMakeLists.txt
+++ b/src/Spatial_searching/example/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 2.6)
project(Spatial_searching_examples)
if(CGAL_FOUND)
- if (NOT CGAL_VERSION VERSION_LESS 4.9.0)
+ if (NOT CGAL_VERSION VERSION_LESS 4.8.1)
if (EIGEN3_FOUND)
add_executable( Spatial_searching_example_spatial_searching example_spatial_searching.cpp )
target_link_libraries(Spatial_searching_example_spatial_searching ${CGAL_LIBRARY})
diff --git a/src/Spatial_searching/test/CMakeLists.txt b/src/Spatial_searching/test/CMakeLists.txt
index 7f443b79..2c685c72 100644
--- a/src/Spatial_searching/test/CMakeLists.txt
+++ b/src/Spatial_searching/test/CMakeLists.txt
@@ -11,7 +11,7 @@ if (GPROF_PATH)
endif()
if(CGAL_FOUND)
- if (NOT CGAL_VERSION VERSION_LESS 4.9.0)
+ if (NOT CGAL_VERSION VERSION_LESS 4.8.1)
if (EIGEN3_FOUND)
add_executable( Spatial_searching_test_Kd_tree_search test_Kd_tree_search.cpp )
target_link_libraries(Spatial_searching_test_Kd_tree_search
diff --git a/src/Subsampling/example/CMakeLists.txt b/src/Subsampling/example/CMakeLists.txt
index 54349f0c..0fd3335c 100644
--- a/src/Subsampling/example/CMakeLists.txt
+++ b/src/Subsampling/example/CMakeLists.txt
@@ -6,6 +6,7 @@ if(CGAL_FOUND)
if (EIGEN3_FOUND)
add_executable(Subsampling_example_pick_n_random_points example_pick_n_random_points.cpp)
add_executable(Subsampling_example_choose_n_farthest_points example_choose_n_farthest_points.cpp)
+ add_executable(Subsampling_example_custom_kernel example_custom_kernel.cpp)
add_executable(Subsampling_example_sparsify_point_set example_sparsify_point_set.cpp)
target_link_libraries(Subsampling_example_sparsify_point_set ${CGAL_LIBRARY})
diff --git a/src/Subsampling/example/example_custom_kernel.cpp b/src/Subsampling/example/example_custom_kernel.cpp
new file mode 100644
index 00000000..05797ebe
--- /dev/null
+++ b/src/Subsampling/example/example_custom_kernel.cpp
@@ -0,0 +1,69 @@
+#include <gudhi/choose_n_farthest_points.h>
+
+#include <CGAL/Epick_d.h>
+#include <CGAL/Random.h>
+
+#include <vector>
+#include <iterator>
+
+
+/* The class Kernel contains a distance function defined on the set of points {0,1,2,3}
+ * and computes a distance according to the matrix:
+ * 0 1 2 4
+ * 1 0 4 2
+ * 2 4 0 1
+ * 4 2 1 0
+ */
+class Kernel {
+public:
+ typedef double FT;
+ typedef unsigned Point_d;
+
+ // Class Squared_distance_d
+ class Squared_distance_d {
+ private:
+ std::vector<std::vector<FT>> matrix_;
+
+ public:
+
+ Squared_distance_d()
+ {
+ matrix_.push_back(std::vector<FT>({0,1,2,4}));
+ matrix_.push_back(std::vector<FT>({1,0,4,2}));
+ matrix_.push_back(std::vector<FT>({2,4,0,1}));
+ matrix_.push_back(std::vector<FT>({4,2,1,0}));
+ }
+
+ FT operator()(Point_d p1, Point_d p2)
+ {
+ return matrix_[p1][p2];
+ }
+ };
+
+ // Constructor
+ Kernel()
+ {}
+
+ // Object of type Squared_distance_d
+ Squared_distance_d squared_distance_d_object() const
+ {
+ return Squared_distance_d();
+ }
+
+};
+
+int main(void) {
+ typedef Kernel K;
+ typedef typename K::Point_d Point_d;
+
+ K k;
+ std::vector<Point_d> points = {0,1,2,3};
+ std::vector<Point_d> results;
+
+ Gudhi::subsampling::choose_n_farthest_points(k, points, 2, std::back_inserter(results));
+ std::cout << "Before sparsification: " << points.size() << " points.\n";
+ std::cout << "After sparsification: " << results.size() << " points.\n";
+ std::cout << "Result table: {" << results[0] << "," << results[1] << "}\n";
+
+ return 0;
+}
diff --git a/src/Subsampling/include/gudhi/choose_n_farthest_points.h b/src/Subsampling/include/gudhi/choose_n_farthest_points.h
index 9b45c640..ea387bf9 100644
--- a/src/Subsampling/include/gudhi/choose_n_farthest_points.h
+++ b/src/Subsampling/include/gudhi/choose_n_farthest_points.h
@@ -48,15 +48,28 @@ namespace subsampling {
* \brief Subsample by a greedy strategy of iteratively adding the farthest point from the
* current chosen point set to the subsampling.
* The iteration starts with the landmark `starting point`.
+ * \tparam Kernel must provide a type Kernel::Squared_distance_d which is a model of the
+ * concept <a target="_blank"
+ * href="http://doc.cgal.org/latest/Kernel_d/classKernel__d_1_1Squared__distance__d.html">Kernel_d::Squared_distance_d</a>
+ * concept.
+ * It must also contain a public member 'squared_distance_d_object' of this type.
+ * \tparam Point_range Range whose value type is Kernel::Point_d. It must provide random-access
+ * via `operator[]` and the points should be stored contiguously in memory.
+ * \tparam OutputIterator Output iterator whose value type is Kernel::Point_d.
* \details It chooses `final_size` points from a random access range `input_pts` and
* outputs it in the output iterator `output_it`.
+ * @param[in] k A kernel object.
+ * @param[in] input_pts Const reference to the input points.
+ * @param[in] final_size The size of the subsample to compute.
+ * @param[in] starting_point The seed in the farthest point algorithm.
+ * @param[out] output_it The output iterator.
*
*/
template < typename Kernel,
-typename Point_container,
+typename Point_range,
typename OutputIterator>
void choose_n_farthest_points(Kernel const &k,
- Point_container const &input_pts,
+ Point_range const &input_pts,
std::size_t final_size,
std::size_t starting_point,
OutputIterator output_it) {
@@ -101,15 +114,27 @@ void choose_n_farthest_points(Kernel const &k,
* \brief Subsample by a greedy strategy of iteratively adding the farthest point from the
* current chosen point set to the subsampling.
* The iteration starts with a random landmark.
+ * \tparam Kernel must provide a type Kernel::Squared_distance_d which is a model of the
+ * concept <a target="_blank"
+ * href="http://doc.cgal.org/latest/Kernel_d/classKernel__d_1_1Squared__distance__d.html">Kernel_d::Squared_distance_d</a>
+ * concept.
+ * It must also contain a public member 'squared_distance_d_object' of this type.
+ * \tparam Point_range Range whose value type is Kernel::Point_d. It must provide random-access
+ * via `operator[]` and the points should be stored contiguously in memory.
+ * \tparam OutputIterator Output iterator whose value type is Kernel::Point_d.
* \details It chooses `final_size` points from a random access range `input_pts` and
* outputs it in the output iterator `output_it`.
+ * @param[in] k A kernel object.
+ * @param[in] input_pts Const reference to the input points.
+ * @param[in] final_size The size of the subsample to compute.
+ * @param[out] output_it The output iterator.
*
*/
template < typename Kernel,
-typename Point_container,
+typename Point_range,
typename OutputIterator>
void choose_n_farthest_points(Kernel const& k,
- Point_container const &input_pts,
+ Point_range const &input_pts,
unsigned final_size,
OutputIterator output_it) {
// Tests to the limit
@@ -120,8 +145,7 @@ void choose_n_farthest_points(Kernel const& k,
std::random_device rd;
std::mt19937 gen(rd());
std::uniform_int_distribution<> dis(0, (input_pts.size() - 1));
- std::size_t starting_point = dis(gen);
-
+ int starting_point = dis(gen);
choose_n_farthest_points(k, input_pts, final_size, starting_point, output_it);
}
diff --git a/src/Subsampling/test/test_choose_n_farthest_points.cpp b/src/Subsampling/test/test_choose_n_farthest_points.cpp
index 0bc0dff4..d064899a 100644
--- a/src/Subsampling/test/test_choose_n_farthest_points.cpp
+++ b/src/Subsampling/test/test_choose_n_farthest_points.cpp
@@ -39,65 +39,18 @@ typedef CGAL::Epick_d<CGAL::Dynamic_dimension_tag> K;
typedef typename K::FT FT;
typedef typename K::Point_d Point_d;
-typedef boost::mpl::list<CGAL::Epick_d<CGAL::Dynamic_dimension_tag>, CGAL::Epick_d<CGAL::Dimension_tag<4>>> list_of_tested_kernels;
-
-BOOST_AUTO_TEST_CASE_TEMPLATE(test_choose_farthest_point, Kernel, list_of_tested_kernels) {
- typedef typename Kernel::FT FT;
- typedef typename Kernel::Point_d Point_d;
+BOOST_AUTO_TEST_CASE(test_choose_farthest_point) {
std::vector< Point_d > points, landmarks;
// Add grid points (625 points)
for (FT i = 0; i < 5; i += 1.0)
for (FT j = 0; j < 5; j += 1.0)
for (FT k = 0; k < 5; k += 1.0)
- for (FT l = 0; l < 5; l += 1.0) {
- std::vector<FT> point({i, j, k, l});
- points.push_back(Point_d(point.begin(), point.end()));
- }
+ for (FT l = 0; l < 5; l += 1.0)
+ points.push_back(Point_d(std::vector<FT>({i, j, k, l})));
landmarks.clear();
- Kernel k;
+ K k;
Gudhi::subsampling::choose_n_farthest_points(k, points, 100, std::back_inserter(landmarks));
BOOST_CHECK(landmarks.size() == 100);
- for (auto landmark : landmarks)
- {
- // Check all landmarks are in points
- BOOST_CHECK(std::find (points.begin(), points.end(), landmark) != points.end());
- }
-}
-
-BOOST_AUTO_TEST_CASE_TEMPLATE(test_choose_farthest_point_limits, Kernel, list_of_tested_kernels) {
- typedef typename Kernel::FT FT;
- typedef typename Kernel::Point_d Point_d;
- std::vector< Point_d > points, landmarks;
- landmarks.clear();
- Kernel k;
- // Choose -1 farthest points in an empty point cloud
- Gudhi::subsampling::choose_n_farthest_points(k, points, -1, std::back_inserter(landmarks));
- BOOST_CHECK(landmarks.size() == 0);
- landmarks.clear();
- // Choose 0 farthest points in an empty point cloud
- Gudhi::subsampling::choose_n_farthest_points(k, points, 0, std::back_inserter(landmarks));
- BOOST_CHECK(landmarks.size() == 0);
- landmarks.clear();
- // Choose 1 farthest points in an empty point cloud
- Gudhi::subsampling::choose_n_farthest_points(k, points, 1, std::back_inserter(landmarks));
- BOOST_CHECK(landmarks.size() == 0);
- landmarks.clear();
-
- std::vector<FT> point({0.0, 0.0, 0.0, 0.0});
- points.push_back(Point_d(point.begin(), point.end()));
- // Choose -1 farthest points in an empty point cloud
- Gudhi::subsampling::choose_n_farthest_points(k, points, -1, std::back_inserter(landmarks));
- BOOST_CHECK(landmarks.size() == 1);
- landmarks.clear();
- // Choose 0 farthest points in a one point cloud
- Gudhi::subsampling::choose_n_farthest_points(k, points, 0, std::back_inserter(landmarks));
- BOOST_CHECK(landmarks.size() == 0);
- landmarks.clear();
- // Choose 1 farthest points in a one point cloud
- Gudhi::subsampling::choose_n_farthest_points(k, points, 1, std::back_inserter(landmarks));
- BOOST_CHECK(landmarks.size() == 1);
- landmarks.clear();
-
}