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-rw-r--r--example/Persistent_cohomology/CMakeLists.txt84
-rw-r--r--example/Persistent_cohomology/README152
-rw-r--r--example/Persistent_cohomology/alpha_complex_3d_persistence.cpp285
-rw-r--r--example/Persistent_cohomology/alpha_complex_persistence.cpp117
-rw-r--r--example/Persistent_cohomology/custom_persistence_sort.cpp116
-rw-r--r--example/Persistent_cohomology/performance_rips_persistence.cpp214
-rw-r--r--example/Persistent_cohomology/periodic_alpha_complex_3d_persistence.cpp313
-rw-r--r--example/Persistent_cohomology/persistence_from_file.cpp144
-rw-r--r--example/Persistent_cohomology/persistence_from_simple_simplex_tree.cpp178
-rw-r--r--example/Persistent_cohomology/plain_homology.cpp95
-rw-r--r--example/Persistent_cohomology/rips_multifield_persistence.cpp158
-rw-r--r--example/Persistent_cohomology/rips_persistence.cpp153
-rw-r--r--example/Persistent_cohomology/rips_persistence_via_boundary_matrix.cpp180
13 files changed, 2189 insertions, 0 deletions
diff --git a/example/Persistent_cohomology/CMakeLists.txt b/example/Persistent_cohomology/CMakeLists.txt
new file mode 100644
index 00000000..d97d1b63
--- /dev/null
+++ b/example/Persistent_cohomology/CMakeLists.txt
@@ -0,0 +1,84 @@
+cmake_minimum_required(VERSION 2.6)
+project(Persistent_cohomology_examples)
+
+# problem with Visual Studio link on Boost program_options
+add_definitions( -DBOOST_ALL_NO_LIB )
+add_definitions( -DBOOST_ALL_DYN_LINK )
+
+add_executable(plain_homology plain_homology.cpp)
+target_link_libraries(plain_homology ${Boost_SYSTEM_LIBRARY})
+
+add_executable(persistence_from_simple_simplex_tree persistence_from_simple_simplex_tree.cpp)
+target_link_libraries(persistence_from_simple_simplex_tree ${Boost_SYSTEM_LIBRARY})
+
+add_executable(rips_persistence rips_persistence.cpp)
+target_link_libraries(rips_persistence ${Boost_SYSTEM_LIBRARY} ${Boost_PROGRAM_OPTIONS_LIBRARY})
+
+add_executable(rips_persistence_via_boundary_matrix rips_persistence_via_boundary_matrix.cpp)
+target_link_libraries(rips_persistence_via_boundary_matrix ${Boost_SYSTEM_LIBRARY} ${Boost_PROGRAM_OPTIONS_LIBRARY})
+
+add_executable(persistence_from_file persistence_from_file.cpp)
+target_link_libraries(persistence_from_file ${Boost_SYSTEM_LIBRARY} ${Boost_PROGRAM_OPTIONS_LIBRARY})
+
+if (TBB_FOUND)
+ target_link_libraries(plain_homology ${TBB_LIBRARIES})
+ target_link_libraries(persistence_from_simple_simplex_tree ${TBB_LIBRARIES})
+ target_link_libraries(rips_persistence ${TBB_LIBRARIES})
+ target_link_libraries(rips_persistence_via_boundary_matrix ${TBB_LIBRARIES})
+ target_link_libraries(persistence_from_file ${TBB_LIBRARIES})
+endif()
+
+add_test(plain_homology ${CMAKE_CURRENT_BINARY_DIR}/plain_homology)
+add_test(persistence_from_simple_simplex_tree ${CMAKE_CURRENT_BINARY_DIR}/persistence_from_simple_simplex_tree 1 0)
+add_test(rips_persistence_3 ${CMAKE_CURRENT_BINARY_DIR}/rips_persistence ${CMAKE_SOURCE_DIR}/data/points/Kl.txt -r 0.2 -d 3 -p 3 -m 100)
+add_test(rips_persistence_via_boundary_matrix_3 ${CMAKE_CURRENT_BINARY_DIR}/rips_persistence_via_boundary_matrix ${CMAKE_SOURCE_DIR}/data/points/tore3D_1307.txt -r 0.3 -d 3 -p 3 -m 100)
+add_test(persistence_from_file_3_2_0 ${CMAKE_CURRENT_BINARY_DIR}/persistence_from_file ${CMAKE_SOURCE_DIR}/data/points/bunny_5000.st -p 2 -m 0)
+add_test(persistence_from_file_3_3_100 ${CMAKE_CURRENT_BINARY_DIR}/persistence_from_file ${CMAKE_SOURCE_DIR}/data/points/bunny_5000.st -p 3 -m 100)
+
+if(GMP_FOUND)
+ if(GMPXX_FOUND)
+ add_executable(rips_multifield_persistence rips_multifield_persistence.cpp )
+ target_link_libraries(rips_multifield_persistence ${Boost_SYSTEM_LIBRARY} ${Boost_PROGRAM_OPTIONS_LIBRARY} ${GMPXX_LIBRARIES} ${GMP_LIBRARIES})
+ add_executable ( performance_rips_persistence performance_rips_persistence.cpp )
+ target_link_libraries(performance_rips_persistence ${Boost_SYSTEM_LIBRARY} ${Boost_PROGRAM_OPTIONS_LIBRARY} ${GMPXX_LIBRARIES} ${GMP_LIBRARIES})
+ if (TBB_FOUND)
+ target_link_libraries(rips_multifield_persistence ${TBB_LIBRARIES})
+ target_link_libraries(performance_rips_persistence ${TBB_LIBRARIES})
+ endif(TBB_FOUND)
+
+ add_test(rips_multifield_persistence_2_71 ${CMAKE_CURRENT_BINARY_DIR}/rips_multifield_persistence ${CMAKE_SOURCE_DIR}/data/points/Kl.txt -r 0.2 -d 3 -p 2 -q 71 -m 100)
+ endif(GMPXX_FOUND)
+endif(GMP_FOUND)
+
+if(CGAL_FOUND)
+ add_executable(alpha_complex_3d_persistence alpha_complex_3d_persistence.cpp)
+ target_link_libraries(alpha_complex_3d_persistence ${Boost_SYSTEM_LIBRARY} ${CGAL_LIBRARY})
+
+ if (TBB_FOUND)
+ target_link_libraries(alpha_complex_3d_persistence ${TBB_LIBRARIES})
+ endif(TBB_FOUND)
+ add_test(alpha_complex_3d_persistence_2_0_5 ${CMAKE_CURRENT_BINARY_DIR}/alpha_complex_3d_persistence ${CMAKE_SOURCE_DIR}/data/points/tore3D_300.off 2 0.45)
+
+
+ if (NOT CGAL_VERSION VERSION_LESS 4.7.0)
+ if (EIGEN3_FOUND)
+ add_executable (alpha_complex_persistence alpha_complex_persistence.cpp)
+ target_link_libraries(alpha_complex_persistence ${Boost_SYSTEM_LIBRARY} ${CGAL_LIBRARY} ${Boost_PROGRAM_OPTIONS_LIBRARY})
+
+ add_executable(periodic_alpha_complex_3d_persistence periodic_alpha_complex_3d_persistence.cpp)
+ target_link_libraries(periodic_alpha_complex_3d_persistence ${Boost_SYSTEM_LIBRARY} ${CGAL_LIBRARY})
+
+ add_executable(custom_persistence_sort custom_persistence_sort.cpp)
+ target_link_libraries(custom_persistence_sort ${Boost_SYSTEM_LIBRARY} ${CGAL_LIBRARY})
+
+ if (TBB_FOUND)
+ target_link_libraries(alpha_complex_persistence ${TBB_LIBRARIES})
+ target_link_libraries(periodic_alpha_complex_3d_persistence ${TBB_LIBRARIES})
+ target_link_libraries(custom_persistence_sort ${TBB_LIBRARIES})
+ endif(TBB_FOUND)
+ add_test(alpha_complex_persistence_2_0_45 ${CMAKE_CURRENT_BINARY_DIR}/alpha_complex_persistence ${CMAKE_SOURCE_DIR}/data/points/tore3D_300.off -m 0.45 -p 2)
+ add_test(periodic_alpha_complex_3d_persistence_2_0 ${CMAKE_CURRENT_BINARY_DIR}/periodic_alpha_complex_3d_persistence ${CMAKE_SOURCE_DIR}/data/points/grid_10_10_10_in_0_1.off ${CMAKE_SOURCE_DIR}/data/points/iso_cuboid_3_in_0_1.txt 2 0)
+ add_test(custom_persistence_sort ${CMAKE_CURRENT_BINARY_DIR}/custom_persistence_sort)
+ endif(EIGEN3_FOUND)
+ endif (NOT CGAL_VERSION VERSION_LESS 4.7.0)
+endif(CGAL_FOUND)
diff --git a/example/Persistent_cohomology/README b/example/Persistent_cohomology/README
new file mode 100644
index 00000000..7803e5ab
--- /dev/null
+++ b/example/Persistent_cohomology/README
@@ -0,0 +1,152 @@
+To build the example, run in a Terminal:
+
+cd /path-to-example/
+cmake .
+make
+
+***********************************************************************************************************************
+Example of use of RIPS:
+
+Computation of the persistent homology with Z/2Z coefficients of the Rips complex on points
+sampling a Klein bottle:
+
+./rips_persistence ../../data/points/Kl.txt -r 0.25 -d 3 -p 2 -m 100
+
+output:
+210 0 0 inf
+210 1 0.0702103 inf
+2 1 0.0702103 inf
+2 2 0.159992 inf
+
+
+Every line is of this format: p1*...*pr dim b d
+where
+ p1*...*pr is the product of prime numbers pi such that the homology feature exists in homology with Z/piZ coefficients.
+ dim is the dimension of the homological feature,
+ b and d are respectively the birth and death of the feature and
+
+
+
+with Z/3Z coefficients:
+
+./rips_persistence ../../data/points/Kl.txt -r 0.25 -d 3 -p 3 -m 100
+
+output:
+3 0 0 inf
+3 1 0.0702103 inf
+
+and the computation with Z/2Z and Z/3Z coefficients simultaneously:
+
+./rips_multifield_persistence ../../data/points/Kl.txt -r 0.25 -d 3 -p 2 -q 3 -m 100
+
+output:
+6 0 0 inf
+6 1 0.0702103 inf
+2 1 0.0702103 inf
+2 2 0.159992 inf
+
+and finally the computation with all Z/pZ for 2 <= p <= 71 (20 first prime numbers):
+
+ ./rips_multifield_persistence ../../data/points/Kl.txt -r 0.25 -d 3 -p 2 -q 71 -m 100
+
+output:
+557940830126698960967415390 0 0 inf
+557940830126698960967415390 1 0.0702103 inf
+2 1 0.0702103 inf
+2 2 0.159992 inf
+
+***********************************************************************************************************************
+Example of use of ALPHA:
+
+For a more verbose mode, please run cmake with option "DEBUG_TRACES=TRUE" and recompile the programs.
+
+1) 3D special case
+------------------
+Computation of the persistent homology with Z/2Z coefficients of the alpha complex on points
+sampling a torus 3D:
+
+./alpha_complex_3d_persistence ../../data/points/tore3D_300.off 2 0.45
+
+output:
+Simplex_tree dim: 3
+2 0 0 inf
+2 1 0.0682162 1.0001
+2 1 0.0934117 1.00003
+2 2 0.56444 1.03938
+
+Here we retrieve expected Betti numbers on a tore 3D:
+Betti numbers[0] = 1
+Betti numbers[1] = 2
+Betti numbers[2] = 1
+
+N.B.: - alpha_complex_3d_persistence accepts only OFF files in 3D dimension.
+ - filtration values are alpha square values
+
+2) d-Dimension case
+-------------------
+Computation of the persistent homology with Z/2Z coefficients of the alpha complex on points
+sampling a torus 3D:
+
+./alpha_complex_persistence -r 32 -p 2 -m 0.45 ../../data/points/tore3D_300.off
+
+output:
+Alpha complex is of dimension 3 - 9273 simplices - 300 vertices.
+Simplex_tree dim: 3
+2 0 0 inf
+2 1 0.0682162 1.0001
+2 1 0.0934117 1.00003
+2 2 0.56444 1.03938
+
+Here we retrieve expected Betti numbers on a tore 3D:
+Betti numbers[0] = 1
+Betti numbers[1] = 2
+Betti numbers[2] = 1
+
+N.B.: - alpha_complex_persistence accepts OFF files in d-Dimension.
+ - filtration values are alpha square values
+
+3) 3D periodic special case
+---------------------------
+./periodic_alpha_complex_3d_persistence ../../data/points/grid_10_10_10_in_0_1.off 3 1.0
+
+output:
+Periodic Delaunay computed.
+Simplex_tree dim: 3
+3 0 0 inf
+3 1 0.0025 inf
+3 1 0.0025 inf
+3 1 0.0025 inf
+3 2 0.005 inf
+3 2 0.005 inf
+3 2 0.005 inf
+3 3 0.0075 inf
+
+Here we retrieve expected Betti numbers on a tore 3D:
+Betti numbers[0] = 1
+Betti numbers[1] = 3
+Betti numbers[2] = 3
+Betti numbers[3] = 1
+
+N.B.: - periodic_alpha_complex_3d_persistence accepts only OFF files in 3D dimension. In this example, the periodic cube
+is hard coded to { x = [0,1]; y = [0,1]; z = [0,1] }
+ - filtration values are alpha square values
+
+***********************************************************************************************************************
+Example of use of PLAIN HOMOLOGY:
+
+This example computes the plain homology of the following simplicial complex without filtration values:
+ /* Complex to build. */
+ /* 1 3 */
+ /* o---o */
+ /* /X\ / */
+ /* o---o o */
+ /* 2 0 4 */
+
+./plain_homology
+
+output:
+2 0 0 inf
+2 0 0 inf
+2 1 0 inf
+
+Here we retrieve the 2 entities {0,1,2,3} and {4} (Betti numbers[0] = 2) and the hole in {0,1,3} (Betti numbers[1] = 1)
diff --git a/example/Persistent_cohomology/alpha_complex_3d_persistence.cpp b/example/Persistent_cohomology/alpha_complex_3d_persistence.cpp
new file mode 100644
index 00000000..48fbb91a
--- /dev/null
+++ b/example/Persistent_cohomology/alpha_complex_3d_persistence.cpp
@@ -0,0 +1,285 @@
+/* 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) 2014 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/>.
+ */
+
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/Persistent_cohomology.h>
+#include <gudhi/Points_3D_off_io.h>
+#include <boost/variant.hpp>
+
+#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
+#include <CGAL/Delaunay_triangulation_3.h>
+#include <CGAL/Alpha_shape_3.h>
+#include <CGAL/iterator.h>
+
+#include <fstream>
+#include <cmath>
+#include <string>
+#include <tuple>
+#include <map>
+#include <utility>
+#include <list>
+#include <vector>
+
+// Alpha_shape_3 templates type definitions
+typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
+typedef CGAL::Alpha_shape_vertex_base_3<Kernel> Vb;
+typedef CGAL::Alpha_shape_cell_base_3<Kernel> Fb;
+typedef CGAL::Triangulation_data_structure_3<Vb, Fb> Tds;
+typedef CGAL::Delaunay_triangulation_3<Kernel, Tds> Triangulation_3;
+typedef CGAL::Alpha_shape_3<Triangulation_3> Alpha_shape_3;
+
+// From file type definition
+typedef Kernel::Point_3 Point_3;
+
+// filtration with alpha values needed type definition
+typedef Alpha_shape_3::FT Alpha_value_type;
+typedef CGAL::Object Object;
+typedef CGAL::Dispatch_output_iterator<
+CGAL::cpp11::tuple<Object, Alpha_value_type>,
+CGAL::cpp11::tuple<std::back_insert_iterator< std::vector<Object> >,
+ std::back_insert_iterator< std::vector<Alpha_value_type> > > > Dispatch;
+typedef Alpha_shape_3::Cell_handle Cell_handle;
+typedef Alpha_shape_3::Facet Facet;
+typedef Alpha_shape_3::Edge Edge_3;
+typedef std::list<Alpha_shape_3::Vertex_handle> Vertex_list;
+
+// gudhi type definition
+typedef Gudhi::Simplex_tree<Gudhi::Simplex_tree_options_fast_persistence> ST;
+typedef ST::Vertex_handle Simplex_tree_vertex;
+typedef std::map<Alpha_shape_3::Vertex_handle, Simplex_tree_vertex > Alpha_shape_simplex_tree_map;
+typedef std::pair<Alpha_shape_3::Vertex_handle, Simplex_tree_vertex> Alpha_shape_simplex_tree_pair;
+typedef std::vector< Simplex_tree_vertex > Simplex_tree_vector_vertex;
+typedef Gudhi::persistent_cohomology::Persistent_cohomology< ST, Gudhi::persistent_cohomology::Field_Zp > PCOH;
+
+Vertex_list from(const Cell_handle& ch) {
+ Vertex_list the_list;
+ for (auto i = 0; i < 4; i++) {
+#ifdef DEBUG_TRACES
+ std::cout << "from cell[" << i << "]=" << ch->vertex(i)->point() << std::endl;
+#endif // DEBUG_TRACES
+ the_list.push_back(ch->vertex(i));
+ }
+ return the_list;
+}
+
+Vertex_list from(const Facet& fct) {
+ Vertex_list the_list;
+ for (auto i = 0; i < 4; i++) {
+ if (fct.second != i) {
+#ifdef DEBUG_TRACES
+ std::cout << "from facet=[" << i << "]" << fct.first->vertex(i)->point() << std::endl;
+#endif // DEBUG_TRACES
+ the_list.push_back(fct.first->vertex(i));
+ }
+ }
+ return the_list;
+}
+
+Vertex_list from(const Edge_3& edg) {
+ Vertex_list the_list;
+ for (auto i = 0; i < 4; i++) {
+ if ((edg.second == i) || (edg.third == i)) {
+#ifdef DEBUG_TRACES
+ std::cout << "from edge[" << i << "]=" << edg.first->vertex(i)->point() << std::endl;
+#endif // DEBUG_TRACES
+ the_list.push_back(edg.first->vertex(i));
+ }
+ }
+ return the_list;
+}
+
+Vertex_list from(const Alpha_shape_3::Vertex_handle& vh) {
+ Vertex_list the_list;
+#ifdef DEBUG_TRACES
+ std::cout << "from vertex=" << vh->point() << std::endl;
+#endif // DEBUG_TRACES
+ the_list.push_back(vh);
+ return the_list;
+}
+
+void usage(char * const progName) {
+ std::cerr << "Usage: " << progName <<
+ " path_to_file_graph coeff_field_characteristic[integer > 0] min_persistence[float >= -1.0]\n";
+ exit(-1);
+}
+
+int main(int argc, char * const argv[]) {
+ // program args management
+ if (argc != 4) {
+ std::cerr << "Error: Number of arguments (" << argc << ") is not correct\n";
+ usage(argv[0]);
+ }
+
+ int coeff_field_characteristic = atoi(argv[2]);
+
+ Filtration_value min_persistence = 0.0;
+ int returnedScanValue = sscanf(argv[3], "%lf", &min_persistence);
+ if ((returnedScanValue == EOF) || (min_persistence < -1.0)) {
+ std::cerr << "Error: " << argv[3] << " is not correct\n";
+ usage(argv[0]);
+ }
+
+ // Read points from file
+ std::string offInputFile(argv[1]);
+ // Read the OFF file (input file name given as parameter) and triangulate points
+ Gudhi::Points_3D_off_reader<Point_3> off_reader(offInputFile);
+ // Check the read operation was correct
+ if (!off_reader.is_valid()) {
+ std::cerr << "Unable to read file " << offInputFile << std::endl;
+ usage(argv[0]);
+ }
+
+ // Retrieve the triangulation
+ std::vector<Point_3> lp = off_reader.get_point_cloud();
+
+ // alpha shape construction from points. CGAL has a strange behavior in REGULARIZED mode.
+ Alpha_shape_3 as(lp.begin(), lp.end(), 0, Alpha_shape_3::GENERAL);
+#ifdef DEBUG_TRACES
+ std::cout << "Alpha shape computed in GENERAL mode" << std::endl;
+#endif // DEBUG_TRACES
+
+ // filtration with alpha values from alpha shape
+ std::vector<Object> the_objects;
+ std::vector<Alpha_value_type> the_alpha_values;
+
+ Dispatch disp = CGAL::dispatch_output<Object, Alpha_value_type>(std::back_inserter(the_objects),
+ std::back_inserter(the_alpha_values));
+
+ as.filtration_with_alpha_values(disp);
+#ifdef DEBUG_TRACES
+ std::cout << "filtration_with_alpha_values returns : " << the_objects.size() << " objects" << std::endl;
+#endif // DEBUG_TRACES
+
+ Alpha_shape_3::size_type count_vertices = 0;
+ Alpha_shape_3::size_type count_edges = 0;
+ Alpha_shape_3::size_type count_facets = 0;
+ Alpha_shape_3::size_type count_cells = 0;
+
+ // Loop on objects vector
+ Vertex_list vertex_list;
+ ST simplex_tree;
+ Alpha_shape_simplex_tree_map map_cgal_simplex_tree;
+ std::vector<Alpha_value_type>::iterator the_alpha_value_iterator = the_alpha_values.begin();
+ int dim_max = 0;
+ Filtration_value filtration_max = 0.0;
+ for (auto object_iterator : the_objects) {
+ // Retrieve Alpha shape vertex list from object
+ if (const Cell_handle * cell = CGAL::object_cast<Cell_handle>(&object_iterator)) {
+ vertex_list = from(*cell);
+ count_cells++;
+ if (dim_max < 3) {
+ // Cell is of dim 3
+ dim_max = 3;
+ }
+ } else if (const Facet * facet = CGAL::object_cast<Facet>(&object_iterator)) {
+ vertex_list = from(*facet);
+ count_facets++;
+ if (dim_max < 2) {
+ // Facet is of dim 2
+ dim_max = 2;
+ }
+ } else if (const Edge_3 * edge = CGAL::object_cast<Edge_3>(&object_iterator)) {
+ vertex_list = from(*edge);
+ count_edges++;
+ if (dim_max < 1) {
+ // Edge_3 is of dim 1
+ dim_max = 1;
+ }
+ } else if (const Alpha_shape_3::Vertex_handle * vertex =
+ CGAL::object_cast<Alpha_shape_3::Vertex_handle>(&object_iterator)) {
+ count_vertices++;
+ vertex_list = from(*vertex);
+ }
+ // Construction of the vector of simplex_tree vertex from list of alpha_shapes vertex
+ Simplex_tree_vector_vertex the_simplex_tree;
+ for (auto the_alpha_shape_vertex : vertex_list) {
+ Alpha_shape_simplex_tree_map::iterator the_map_iterator = map_cgal_simplex_tree.find(the_alpha_shape_vertex);
+ if (the_map_iterator == map_cgal_simplex_tree.end()) {
+ // alpha shape not found
+ Simplex_tree_vertex vertex = map_cgal_simplex_tree.size();
+#ifdef DEBUG_TRACES
+ std::cout << "vertex [" << the_alpha_shape_vertex->point() << "] not found - insert " << vertex << std::endl;
+#endif // DEBUG_TRACES
+ the_simplex_tree.push_back(vertex);
+ map_cgal_simplex_tree.insert(Alpha_shape_simplex_tree_pair(the_alpha_shape_vertex, vertex));
+ } else {
+ // alpha shape found
+ Simplex_tree_vertex vertex = the_map_iterator->second;
+#ifdef DEBUG_TRACES
+ std::cout << "vertex [" << the_alpha_shape_vertex->point() << "] found in " << vertex << std::endl;
+#endif // DEBUG_TRACES
+ the_simplex_tree.push_back(vertex);
+ }
+ }
+ // Construction of the simplex_tree
+ Filtration_value filtr = /*std::sqrt*/(*the_alpha_value_iterator);
+#ifdef DEBUG_TRACES
+ std::cout << "filtration = " << filtr << std::endl;
+#endif // DEBUG_TRACES
+ if (filtr > filtration_max) {
+ filtration_max = filtr;
+ }
+ simplex_tree.insert_simplex(the_simplex_tree, filtr);
+ if (the_alpha_value_iterator != the_alpha_values.end())
+ ++the_alpha_value_iterator;
+ else
+ std::cout << "This shall not happen" << std::endl;
+ }
+ simplex_tree.set_filtration(filtration_max);
+ simplex_tree.set_dimension(dim_max);
+
+#ifdef DEBUG_TRACES
+ std::cout << "vertices \t\t" << count_vertices << std::endl;
+ std::cout << "edges \t\t" << count_edges << std::endl;
+ std::cout << "facets \t\t" << count_facets << std::endl;
+ std::cout << "cells \t\t" << count_cells << std::endl;
+
+
+ std::cout << "Information of the Simplex Tree: " << std::endl;
+ std::cout << " Number of vertices = " << simplex_tree.num_vertices() << " ";
+ std::cout << " Number of simplices = " << simplex_tree.num_simplices() << std::endl << std::endl;
+ std::cout << " Dimension = " << simplex_tree.dimension() << " ";
+ std::cout << " filtration = " << simplex_tree.filtration() << std::endl << std::endl;
+#endif // DEBUG_TRACES
+
+#ifdef DEBUG_TRACES
+ std::cout << "Iterator on vertices: " << std::endl;
+ for (auto vertex : simplex_tree.complex_vertex_range()) {
+ std::cout << vertex << " ";
+ }
+#endif // DEBUG_TRACES
+
+ // Sort the simplices in the order of the filtration
+ simplex_tree.initialize_filtration();
+
+ std::cout << "Simplex_tree dim: " << simplex_tree.dimension() << std::endl;
+ // Compute the persistence diagram of the complex
+ PCOH pcoh(simplex_tree);
+ // initializes the coefficient field for homology
+ pcoh.init_coefficients(coeff_field_characteristic);
+
+ pcoh.compute_persistent_cohomology(min_persistence);
+
+ pcoh.output_diagram();
+
+ return 0;
+}
diff --git a/example/Persistent_cohomology/alpha_complex_persistence.cpp b/example/Persistent_cohomology/alpha_complex_persistence.cpp
new file mode 100644
index 00000000..cb181936
--- /dev/null
+++ b/example/Persistent_cohomology/alpha_complex_persistence.cpp
@@ -0,0 +1,117 @@
+#include <boost/program_options.hpp>
+
+#include <CGAL/Epick_d.h>
+
+#include <gudhi/Alpha_complex.h>
+#include <gudhi/Persistent_cohomology.h>
+
+#include <iostream>
+#include <string>
+#include <limits> // for numeric_limits
+
+void program_options(int argc, char * argv[]
+ , std::string & off_file_points
+ , std::string & output_file_diag
+ , Filtration_value & alpha_square_max_value
+ , int & coeff_field_characteristic
+ , Filtration_value & min_persistence);
+
+int main(int argc, char **argv) {
+ std::string off_file_points;
+ std::string output_file_diag;
+ Filtration_value alpha_square_max_value;
+ int coeff_field_characteristic;
+ Filtration_value min_persistence;
+
+ program_options(argc, argv, off_file_points, output_file_diag, alpha_square_max_value,
+ coeff_field_characteristic, min_persistence);
+
+ // ----------------------------------------------------------------------------
+ // Init of an alpha complex from an OFF file
+ // ----------------------------------------------------------------------------
+ using Kernel = CGAL::Epick_d< CGAL::Dynamic_dimension_tag >;
+ Gudhi::alpha_complex::Alpha_complex<Kernel> alpha_complex_from_file(off_file_points, alpha_square_max_value);
+
+ // ----------------------------------------------------------------------------
+ // Display information about the alpha complex
+ // ----------------------------------------------------------------------------
+ std::cout << "Alpha complex is of dimension " << alpha_complex_from_file.dimension() <<
+ " - " << alpha_complex_from_file.num_simplices() << " simplices - " <<
+ alpha_complex_from_file.num_vertices() << " vertices." << std::endl;
+
+ // Sort the simplices in the order of the filtration
+ alpha_complex_from_file.initialize_filtration();
+
+ std::cout << "Simplex_tree dim: " << alpha_complex_from_file.dimension() << std::endl;
+ // Compute the persistence diagram of the complex
+ Gudhi::persistent_cohomology::Persistent_cohomology< Gudhi::alpha_complex::Alpha_complex<Kernel>,
+ Gudhi::persistent_cohomology::Field_Zp > pcoh(alpha_complex_from_file);
+ // initializes the coefficient field for homology
+ pcoh.init_coefficients(coeff_field_characteristic);
+
+ pcoh.compute_persistent_cohomology(min_persistence);
+
+ // Output the diagram in filediag
+ if (output_file_diag.empty()) {
+ pcoh.output_diagram();
+ } else {
+ std::cout << "Result in file: " << output_file_diag << std::endl;
+ std::ofstream out(output_file_diag);
+ pcoh.output_diagram(out);
+ out.close();
+ }
+
+ return 0;
+}
+
+void program_options(int argc, char * argv[]
+ , std::string & off_file_points
+ , std::string & output_file_diag
+ , Filtration_value & alpha_square_max_value
+ , int & coeff_field_characteristic
+ , Filtration_value & min_persistence) {
+ namespace po = boost::program_options;
+ po::options_description hidden("Hidden options");
+ hidden.add_options()
+ ("input-file", po::value<std::string>(&off_file_points),
+ "Name of file containing a point set. Format is one point per line: X1 ... Xd ");
+
+ po::options_description visible("Allowed options", 100);
+ visible.add_options()
+ ("help,h", "produce help message")
+ ("output-file,o", po::value<std::string>(&output_file_diag)->default_value(std::string()),
+ "Name of file in which the persistence diagram is written. Default print in std::cout")
+ ("max-alpha-square-value,r",
+ po::value<Filtration_value>(&alpha_square_max_value)->default_value(std::numeric_limits<Filtration_value>::infinity()),
+ "Maximal alpha square value for the Alpha complex construction.")
+ ("field-charac,p", po::value<int>(&coeff_field_characteristic)->default_value(11),
+ "Characteristic p of the coefficient field Z/pZ for computing homology.")
+ ("min-persistence,m", po::value<Filtration_value>(&min_persistence),
+ "Minimal lifetime of homology feature to be recorded. Default is 0. Enter a negative value to see zero length intervals");
+
+ po::positional_options_description pos;
+ pos.add("input-file", 1);
+
+ po::options_description all;
+ all.add(visible).add(hidden);
+
+ po::variables_map vm;
+ po::store(po::command_line_parser(argc, argv).
+ options(all).positional(pos).run(), vm);
+ po::notify(vm);
+
+ if (vm.count("help") || !vm.count("input-file")) {
+ std::cout << std::endl;
+ std::cout << "Compute the persistent homology with coefficient field Z/pZ \n";
+ std::cout << "of an Alpha complex defined on a set of input points.\n \n";
+ std::cout << "The output diagram contains one bar per line, written with the convention: \n";
+ std::cout << " p dim b d \n";
+ std::cout << "where dim is the dimension of the homological feature,\n";
+ std::cout << "b and d are respectively the birth and death of the feature and \n";
+ std::cout << "p is the characteristic of the field Z/pZ used for homology coefficients." << std::endl << std::endl;
+
+ std::cout << "Usage: " << argv[0] << " [options] input-file" << std::endl << std::endl;
+ std::cout << visible << std::endl;
+ std::abort();
+ }
+}
diff --git a/example/Persistent_cohomology/custom_persistence_sort.cpp b/example/Persistent_cohomology/custom_persistence_sort.cpp
new file mode 100644
index 00000000..9af38611
--- /dev/null
+++ b/example/Persistent_cohomology/custom_persistence_sort.cpp
@@ -0,0 +1,116 @@
+/* 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) 2014 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/>.
+ */
+
+#include <CGAL/Epick_d.h>
+#include <CGAL/point_generators_d.h>
+#include <CGAL/algorithm.h>
+#include <CGAL/assertions.h>
+
+#include <gudhi/Alpha_complex.h>
+#include <gudhi/Persistent_cohomology.h>
+
+#include <iostream>
+#include <iterator>
+#include <vector>
+#include <fstream> // for std::ofstream
+#include <algorithm> // for std::sort
+
+
+using Kernel = CGAL::Epick_d< CGAL::Dimension_tag<3> >;
+using Point = Kernel::Point_d;
+using Alpha_complex = Gudhi::alpha_complex::Alpha_complex<Kernel>;
+
+std::vector<Point> random_points() {
+ // Instanciate a random point generator
+ CGAL::Random rng(0);
+
+ // Generate "points_number" random points in a vector
+ std::vector<Point> points;
+
+ // Generates 1000 random 3D points on a sphere of radius 4.0
+ CGAL::Random_points_on_sphere_d<Point> rand_outside(3, 4.0, rng);
+ CGAL::cpp11::copy_n(rand_outside, 1000, std::back_inserter(points));
+ // Generates 2000 random 3D points in a sphere of radius 3.0
+ CGAL::Random_points_in_ball_d<Point> rand_inside(3, 3.0, rng);
+ CGAL::cpp11::copy_n(rand_inside, 2000, std::back_inserter(points));
+
+ return points;
+}
+
+/*
+ * Compare two intervals by dimension, then by length.
+ */
+struct cmp_intervals_by_dim_then_length {
+ explicit cmp_intervals_by_dim_then_length(Alpha_complex * sc)
+ : sc_(sc) { }
+
+ template<typename Persistent_interval>
+ bool operator()(const Persistent_interval & p1, const Persistent_interval & p2) {
+ if (sc_->dimension(get < 0 > (p1)) == sc_->dimension(get < 0 > (p2)))
+ return (sc_->filtration(get < 1 > (p1)) - sc_->filtration(get < 0 > (p1))
+ > sc_->filtration(get < 1 > (p2)) - sc_->filtration(get < 0 > (p2)));
+ else
+ return (sc_->dimension(get < 0 > (p1)) > sc_->dimension(get < 0 > (p2)));
+ }
+ Alpha_complex* sc_;
+};
+
+int main(int argc, char **argv) {
+ std::vector<Point> points = random_points();
+
+ // Alpha complex persistence computation from generated points
+ Alpha_complex alpha_complex_from_points(points, 0.6);
+
+ using Persistent_cohomology = Gudhi::persistent_cohomology::Persistent_cohomology< Alpha_complex,
+ Gudhi::persistent_cohomology::Field_Zp >;
+ Persistent_cohomology pcoh(alpha_complex_from_points);
+
+ // initializes the coefficient field for homology - Z/3Z
+ pcoh.init_coefficients(3);
+ pcoh.compute_persistent_cohomology(0.2);
+
+ // Custom sort and output persistence
+ cmp_intervals_by_dim_then_length cmp(&alpha_complex_from_points);
+ auto persistent_pairs = pcoh.get_persistent_pairs();
+ std::sort(std::begin(persistent_pairs), std::end(persistent_pairs), cmp);
+ for (auto pair : persistent_pairs) {
+ std::cout << alpha_complex_from_points.dimension(get<0>(pair)) << " "
+ << alpha_complex_from_points.filtration(get<0>(pair)) << " "
+ << alpha_complex_from_points.filtration(get<1>(pair)) << std::endl;
+ }
+
+ // Persistent Betti numbers
+ std::cout << "The persistent Betti numbers in interval [0.40, 0.41] are : ";
+ for (int dim = 0; dim < alpha_complex_from_points.dimension(); dim++)
+ std::cout << "b" << dim << " = " << pcoh.persistent_betti_number(dim, 0.40, 0.41) << " ; ";
+ std::cout << std::endl;
+
+ // Betti numbers
+ std::vector<int> betti_numbers = pcoh.betti_numbers();
+ std::cout << "The Betti numbers are : ";
+ for (std::size_t i = 0; i < betti_numbers.size(); i++)
+ std::cout << "b" << i << " = " << betti_numbers[i] << " ; ";
+ std::cout << std::endl;
+
+ return 0;
+}
+
diff --git a/example/Persistent_cohomology/performance_rips_persistence.cpp b/example/Persistent_cohomology/performance_rips_persistence.cpp
new file mode 100644
index 00000000..b4d282ac
--- /dev/null
+++ b/example/Persistent_cohomology/performance_rips_persistence.cpp
@@ -0,0 +1,214 @@
+/* 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): Clément Maria
+ *
+ * Copyright (C) 2014 INRIA Sophia Antipolis-Méditerranée (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/>.
+ */
+
+#include <gudhi/reader_utils.h>
+#include <gudhi/graph_simplicial_complex.h>
+#include <gudhi/distance_functions.h>
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/Persistent_cohomology.h>
+#include <gudhi/Persistent_cohomology/Multi_field.h>
+#include <gudhi/Hasse_complex.h>
+
+#include <chrono>
+#include <string>
+#include <vector>
+
+using namespace Gudhi;
+using namespace Gudhi::persistent_cohomology;
+
+/* Compute the persistent homology of the complex cpx with coefficients in Z/pZ. */
+template< typename FilteredComplex>
+void timing_persistence(FilteredComplex & cpx
+ , int p);
+
+/* Compute multi-field persistent homology of the complex cpx with coefficients in
+ * Z/rZ for all prime number r in [p;q].*/
+template< typename FilteredComplex>
+void timing_persistence(FilteredComplex & cpx
+ , int p
+ , int q);
+
+/* Timings for the computation of persistent homology with different
+ * representations of a Rips complex and different coefficient fields. The
+ * Rips complex is built on a set of 10000 points sampling a Klein bottle embedded
+ * in dimension 5.
+ * We represent complexes with a simplex tree and
+ * with a Hasse diagram. The Hasse diagram represents explicitly all
+ * codimension 1 incidence relations in the complex, and hence leads to
+ * a faster computation of persistence because boundaries are precomputed.
+ * Hovewer, the simplex tree may be constructed directly from a point cloud and
+ * is more compact.
+ * We compute persistent homology with coefficient fields Z/2Z and Z/1223Z.
+ * We present also timings for the computation of multi-field persistent
+ * homology in all fields Z/rZ for r prime between 2 and 1223.
+ */
+int main(int argc, char * argv[]) {
+ std::chrono::time_point<std::chrono::system_clock> start, end;
+ int elapsed_sec;
+ {
+
+ std::string filepoints = "../../../data/points/Kl.txt";
+ Filtration_value threshold = 0.27;
+ int dim_max = 3;
+ int p = 2;
+ int q = 1223;
+
+ // Extract the points from the file filepoints
+ typedef std::vector<double> Point_t;
+ std::vector< Point_t > points;
+ read_points(filepoints, points);
+
+ // Compute the proximity graph of the points
+ start = std::chrono::system_clock::now();
+ Graph_t prox_graph = compute_proximity_graph(points, threshold
+ , euclidean_distance<Point_t>);
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << "Compute Rips graph in " << elapsed_sec << " ms.\n";
+
+ // Construct the Rips complex in a Simplex Tree
+ Simplex_tree<Simplex_tree_options_fast_persistence> st;
+ start = std::chrono::system_clock::now();
+
+ // insert the proximity graph in the simplex tree
+ st.insert_graph(prox_graph);
+ // expand the graph until dimension dim_max
+ st.expansion(dim_max);
+
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << "Compute Rips complex in " << elapsed_sec << " ms.\n";
+ std::cout << " - dimension = " << st.dimension() << std::endl;
+ std::cout << " - number of simplices = " << st.num_simplices() << std::endl;
+
+ // Sort the simplices in the order of the filtration
+ start = std::chrono::system_clock::now();
+ st.initialize_filtration();
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << "Order the simplices of the filtration in " << elapsed_sec << " ms.\n";
+
+ // Copy the keys inside the simplices
+ start = std::chrono::system_clock::now();
+ {
+ int count = 0;
+ for (auto sh : st.filtration_simplex_range())
+ st.assign_key(sh, count++);
+ }
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << "Copied the keys inside the simplices in " << elapsed_sec << " ms.\n";
+
+ // Convert the simplex tree into a hasse diagram
+ start = std::chrono::system_clock::now();
+ Hasse_complex<> hcpx(st);
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << "Convert the simplex tree into a Hasse diagram in " << elapsed_sec << " ms.\n";
+
+
+ std::cout << "Timings when using a simplex tree: \n";
+ timing_persistence(st, p);
+ timing_persistence(st, q);
+ timing_persistence(st, p, q);
+
+ std::cout << "Timings when using a Hasse complex: \n";
+ timing_persistence(hcpx, p);
+ timing_persistence(hcpx, q);
+ timing_persistence(hcpx, p, q);
+
+ start = std::chrono::system_clock::now();
+ }
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << "Running the complex destructors in " << elapsed_sec << " ms.\n";
+ return 0;
+}
+
+template< typename FilteredComplex>
+void
+timing_persistence(FilteredComplex & cpx
+ , int p) {
+ std::chrono::time_point<std::chrono::system_clock> start, end;
+ int elapsed_sec;
+ {
+ start = std::chrono::system_clock::now();
+ Persistent_cohomology< FilteredComplex, Field_Zp > pcoh(cpx);
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << " Initialize pcoh in " << elapsed_sec << " ms.\n";
+ // initializes the coefficient field for homology
+ start = std::chrono::system_clock::now();
+ pcoh.init_coefficients(p);
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << " Initialize the coefficient field in " << elapsed_sec << " ms.\n";
+
+ start = std::chrono::system_clock::now();
+
+ pcoh.compute_persistent_cohomology(INFINITY);
+
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << " Compute persistent homology in Z/" << p << "Z in " << elapsed_sec << " ms.\n";
+ start = std::chrono::system_clock::now();
+ }
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << " Run the persistence destructors in " << elapsed_sec << " ms.\n";
+}
+
+template< typename FilteredComplex>
+void
+timing_persistence(FilteredComplex & cpx
+ , int p
+ , int q) {
+ std::chrono::time_point<std::chrono::system_clock> start, end;
+ int elapsed_sec;
+ {
+ start = std::chrono::system_clock::now();
+ Persistent_cohomology< FilteredComplex, Multi_field > pcoh(cpx);
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << " Initialize pcoh in " << elapsed_sec << " ms.\n";
+ // initializes the coefficient field for homology
+ start = std::chrono::system_clock::now();
+ pcoh.init_coefficients(p, q);
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << " Initialize the coefficient field in " << elapsed_sec << " ms.\n";
+ // compute persistent homology, disgarding persistent features of life shorter than min_persistence
+
+ start = std::chrono::system_clock::now();
+
+ pcoh.compute_persistent_cohomology(INFINITY);
+
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << " Compute multi-field persistent homology in all coefficient fields Z/pZ "
+ << "with p in [" << p << ";" << q << "] in " << elapsed_sec << " ms.\n";
+ start = std::chrono::system_clock::now();
+ }
+ end = std::chrono::system_clock::now();
+ elapsed_sec = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
+ std::cout << " Run the persistence destructors in " << elapsed_sec << " ms.\n";
+}
diff --git a/example/Persistent_cohomology/periodic_alpha_complex_3d_persistence.cpp b/example/Persistent_cohomology/periodic_alpha_complex_3d_persistence.cpp
new file mode 100644
index 00000000..a199fea1
--- /dev/null
+++ b/example/Persistent_cohomology/periodic_alpha_complex_3d_persistence.cpp
@@ -0,0 +1,313 @@
+/* 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) 2014 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/>.
+ */
+
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/Persistent_cohomology.h>
+#include <gudhi/Points_3D_off_io.h>
+#include <boost/variant.hpp>
+
+#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
+#include <CGAL/Periodic_3_Delaunay_triangulation_traits_3.h>
+#include <CGAL/Periodic_3_Delaunay_triangulation_3.h>
+#include <CGAL/Alpha_shape_3.h>
+#include <CGAL/iterator.h>
+
+#include <fstream>
+#include <cmath>
+#include <string>
+#include <tuple>
+#include <map>
+#include <utility>
+#include <list>
+#include <vector>
+
+// Traits
+using K = CGAL::Exact_predicates_inexact_constructions_kernel;
+using PK = CGAL::Periodic_3_Delaunay_triangulation_traits_3<K>;
+// Vertex type
+using DsVb = CGAL::Periodic_3_triangulation_ds_vertex_base_3<>;
+using Vb = CGAL::Triangulation_vertex_base_3<PK, DsVb>;
+using AsVb = CGAL::Alpha_shape_vertex_base_3<PK, Vb>;
+// Cell type
+using DsCb = CGAL::Periodic_3_triangulation_ds_cell_base_3<>;
+using Cb = CGAL::Triangulation_cell_base_3<PK, DsCb>;
+using AsCb = CGAL::Alpha_shape_cell_base_3<PK, Cb>;
+using Tds = CGAL::Triangulation_data_structure_3<AsVb, AsCb>;
+using P3DT3 = CGAL::Periodic_3_Delaunay_triangulation_3<PK, Tds>;
+using Alpha_shape_3 = CGAL::Alpha_shape_3<P3DT3>;
+using Point_3 = PK::Point_3;
+
+// filtration with alpha values needed type definition
+using Alpha_value_type = Alpha_shape_3::FT;
+using Object = CGAL::Object;
+using Dispatch = CGAL::Dispatch_output_iterator<
+ CGAL::cpp11::tuple<Object, Alpha_value_type>,
+ CGAL::cpp11::tuple<std::back_insert_iterator< std::vector<Object> >,
+ std::back_insert_iterator< std::vector<Alpha_value_type> > > >;
+using Cell_handle = Alpha_shape_3::Cell_handle;
+using Facet = Alpha_shape_3::Facet;
+using Edge_3 = Alpha_shape_3::Edge;
+using Vertex_list = std::list<Alpha_shape_3::Vertex_handle>;
+
+// gudhi type definition
+using ST = Gudhi::Simplex_tree<Gudhi::Simplex_tree_options_fast_persistence>;
+using Simplex_tree_vertex = ST::Vertex_handle;
+using Alpha_shape_simplex_tree_map = std::map<Alpha_shape_3::Vertex_handle, Simplex_tree_vertex >;
+using Alpha_shape_simplex_tree_pair = std::pair<Alpha_shape_3::Vertex_handle, Simplex_tree_vertex>;
+using Simplex_tree_vector_vertex = std::vector< Simplex_tree_vertex >;
+using Persistent_cohomology = Gudhi::persistent_cohomology::Persistent_cohomology<
+ ST, Gudhi::persistent_cohomology::Field_Zp >;
+
+Vertex_list from(const Cell_handle& ch) {
+ Vertex_list the_list;
+ for (auto i = 0; i < 4; i++) {
+#ifdef DEBUG_TRACES
+ std::cout << "from cell[" << i << "]=" << ch->vertex(i)->point() << std::endl;
+#endif // DEBUG_TRACES
+ the_list.push_back(ch->vertex(i));
+ }
+ return the_list;
+}
+
+Vertex_list from(const Facet& fct) {
+ Vertex_list the_list;
+ for (auto i = 0; i < 4; i++) {
+ if (fct.second != i) {
+#ifdef DEBUG_TRACES
+ std::cout << "from facet=[" << i << "]" << fct.first->vertex(i)->point() << std::endl;
+#endif // DEBUG_TRACES
+ the_list.push_back(fct.first->vertex(i));
+ }
+ }
+ return the_list;
+}
+
+Vertex_list from(const Edge_3& edg) {
+ Vertex_list the_list;
+ for (auto i = 0; i < 4; i++) {
+ if ((edg.second == i) || (edg.third == i)) {
+#ifdef DEBUG_TRACES
+ std::cout << "from edge[" << i << "]=" << edg.first->vertex(i)->point() << std::endl;
+#endif // DEBUG_TRACES
+ the_list.push_back(edg.first->vertex(i));
+ }
+ }
+ return the_list;
+}
+
+Vertex_list from(const Alpha_shape_3::Vertex_handle& vh) {
+ Vertex_list the_list;
+#ifdef DEBUG_TRACES
+ std::cout << "from vertex=" << vh->point() << std::endl;
+#endif // DEBUG_TRACES
+ the_list.push_back(vh);
+ return the_list;
+}
+
+void usage(char * const progName) {
+ std::cerr << "Usage: " << progName <<
+ " path_to_file_graph path_to_iso_cuboid_3_file coeff_field_characteristic[integer > 0] min_persistence[float >= -1.0]\n";
+ exit(-1);
+}
+
+int main(int argc, char * const argv[]) {
+ // program args management
+ if (argc != 5) {
+ std::cerr << "Error: Number of arguments (" << argc << ") is not correct\n";
+ usage(argv[0]);
+ }
+
+ int coeff_field_characteristic = 0;
+ int returnedScanValue = sscanf(argv[3], "%d", &coeff_field_characteristic);
+ if ((returnedScanValue == EOF) || (coeff_field_characteristic <= 0)) {
+ std::cerr << "Error: " << argv[3] << " is not correct\n";
+ usage(argv[0]);
+ }
+
+ Filtration_value min_persistence = 0.0;
+ returnedScanValue = sscanf(argv[4], "%lf", &min_persistence);
+ if ((returnedScanValue == EOF) || (min_persistence < -1.0)) {
+ std::cerr << "Error: " << argv[4] << " is not correct\n";
+ usage(argv[0]);
+ }
+
+ // Read points from file
+ std::string offInputFile(argv[1]);
+ // Read the OFF file (input file name given as parameter) and triangulate points
+ Gudhi::Points_3D_off_reader<Point_3> off_reader(offInputFile);
+ // Check the read operation was correct
+ if (!off_reader.is_valid()) {
+ std::cerr << "Unable to read file " << offInputFile << std::endl;
+ usage(argv[0]);
+ }
+
+ // Read iso_cuboid_3 information from file
+ std::ifstream iso_cuboid_str(argv[2]);
+ double x_min, y_min, z_min, x_max, y_max, z_max;
+ if (iso_cuboid_str.good()) {
+ iso_cuboid_str >> x_min >> y_min >> z_min >> x_max >> y_max >> z_max;
+ } else {
+ std::cerr << "Unable to read file " << argv[2] << std::endl;
+ usage(argv[0]);
+ }
+
+ // Retrieve the triangulation
+ std::vector<Point_3> lp = off_reader.get_point_cloud();
+
+ // Define the periodic cube
+ P3DT3 pdt(PK::Iso_cuboid_3(x_min, y_min, z_min, x_max, y_max, z_max));
+ // Heuristic for inserting large point sets (if pts is reasonably large)
+ pdt.insert(lp.begin(), lp.end(), true);
+ // As pdt won't be modified anymore switch to 1-sheeted cover if possible
+ if (pdt.is_triangulation_in_1_sheet()) pdt.convert_to_1_sheeted_covering();
+ std::cout << "Periodic Delaunay computed." << std::endl;
+
+ // alpha shape construction from points. CGAL has a strange behavior in REGULARIZED mode. This is the default mode
+ // Maybe need to set it to GENERAL mode
+ Alpha_shape_3 as(pdt, 0, Alpha_shape_3::GENERAL);
+
+ // filtration with alpha values from alpha shape
+ std::vector<Object> the_objects;
+ std::vector<Alpha_value_type> the_alpha_values;
+
+ Dispatch disp = CGAL::dispatch_output<Object, Alpha_value_type>(std::back_inserter(the_objects),
+ std::back_inserter(the_alpha_values));
+
+ as.filtration_with_alpha_values(disp);
+#ifdef DEBUG_TRACES
+ std::cout << "filtration_with_alpha_values returns : " << the_objects.size() << " objects" << std::endl;
+#endif // DEBUG_TRACES
+
+ Alpha_shape_3::size_type count_vertices = 0;
+ Alpha_shape_3::size_type count_edges = 0;
+ Alpha_shape_3::size_type count_facets = 0;
+ Alpha_shape_3::size_type count_cells = 0;
+
+ // Loop on objects vector
+ Vertex_list vertex_list;
+ ST simplex_tree;
+ Alpha_shape_simplex_tree_map map_cgal_simplex_tree;
+ std::vector<Alpha_value_type>::iterator the_alpha_value_iterator = the_alpha_values.begin();
+ int dim_max = 0;
+ Filtration_value filtration_max = 0.0;
+ for (auto object_iterator : the_objects) {
+ // Retrieve Alpha shape vertex list from object
+ if (const Cell_handle * cell = CGAL::object_cast<Cell_handle>(&object_iterator)) {
+ vertex_list = from(*cell);
+ count_cells++;
+ if (dim_max < 3) {
+ // Cell is of dim 3
+ dim_max = 3;
+ }
+ } else if (const Facet * facet = CGAL::object_cast<Facet>(&object_iterator)) {
+ vertex_list = from(*facet);
+ count_facets++;
+ if (dim_max < 2) {
+ // Facet is of dim 2
+ dim_max = 2;
+ }
+ } else if (const Edge_3 * edge = CGAL::object_cast<Edge_3>(&object_iterator)) {
+ vertex_list = from(*edge);
+ count_edges++;
+ if (dim_max < 1) {
+ // Edge_3 is of dim 1
+ dim_max = 1;
+ }
+ } else if (const Alpha_shape_3::Vertex_handle * vertex =
+ CGAL::object_cast<Alpha_shape_3::Vertex_handle>(&object_iterator)) {
+ count_vertices++;
+ vertex_list = from(*vertex);
+ }
+ // Construction of the vector of simplex_tree vertex from list of alpha_shapes vertex
+ Simplex_tree_vector_vertex the_simplex_tree;
+ for (auto the_alpha_shape_vertex : vertex_list) {
+ Alpha_shape_simplex_tree_map::iterator the_map_iterator = map_cgal_simplex_tree.find(the_alpha_shape_vertex);
+ if (the_map_iterator == map_cgal_simplex_tree.end()) {
+ // alpha shape not found
+ Simplex_tree_vertex vertex = map_cgal_simplex_tree.size();
+#ifdef DEBUG_TRACES
+ std::cout << "vertex [" << the_alpha_shape_vertex->point() << "] not found - insert " << vertex << std::endl;
+#endif // DEBUG_TRACES
+ the_simplex_tree.push_back(vertex);
+ map_cgal_simplex_tree.insert(Alpha_shape_simplex_tree_pair(the_alpha_shape_vertex, vertex));
+ } else {
+ // alpha shape found
+ Simplex_tree_vertex vertex = the_map_iterator->second;
+#ifdef DEBUG_TRACES
+ std::cout << "vertex [" << the_alpha_shape_vertex->point() << "] found in " << vertex << std::endl;
+#endif // DEBUG_TRACES
+ the_simplex_tree.push_back(vertex);
+ }
+ }
+ // Construction of the simplex_tree
+ Filtration_value filtr = /*std::sqrt*/(*the_alpha_value_iterator);
+#ifdef DEBUG_TRACES
+ std::cout << "filtration = " << filtr << std::endl;
+#endif // DEBUG_TRACES
+ if (filtr > filtration_max) {
+ filtration_max = filtr;
+ }
+ simplex_tree.insert_simplex(the_simplex_tree, filtr);
+ if (the_alpha_value_iterator != the_alpha_values.end())
+ ++the_alpha_value_iterator;
+ else
+ std::cout << "This shall not happen" << std::endl;
+ }
+ simplex_tree.set_filtration(filtration_max);
+ simplex_tree.set_dimension(dim_max);
+
+#ifdef DEBUG_TRACES
+ std::cout << "vertices \t\t" << count_vertices << std::endl;
+ std::cout << "edges \t\t" << count_edges << std::endl;
+ std::cout << "facets \t\t" << count_facets << std::endl;
+ std::cout << "cells \t\t" << count_cells << std::endl;
+
+
+ std::cout << "Information of the Simplex Tree: " << std::endl;
+ std::cout << " Number of vertices = " << simplex_tree.num_vertices() << " ";
+ std::cout << " Number of simplices = " << simplex_tree.num_simplices() << std::endl << std::endl;
+ std::cout << " Dimension = " << simplex_tree.dimension() << " ";
+ std::cout << " filtration = " << simplex_tree.filtration() << std::endl << std::endl;
+#endif // DEBUG_TRACES
+
+#ifdef DEBUG_TRACES
+ std::cout << "Iterator on vertices: " << std::endl;
+ for (auto vertex : simplex_tree.complex_vertex_range()) {
+ std::cout << vertex << " ";
+ }
+#endif // DEBUG_TRACES
+
+ // Sort the simplices in the order of the filtration
+ simplex_tree.initialize_filtration();
+
+ std::cout << "Simplex_tree dim: " << simplex_tree.dimension() << std::endl;
+ // Compute the persistence diagram of the complex
+ Persistent_cohomology pcoh(simplex_tree, true);
+ // initializes the coefficient field for homology
+ pcoh.init_coefficients(coeff_field_characteristic);
+
+ pcoh.compute_persistent_cohomology(min_persistence);
+
+ pcoh.output_diagram();
+
+ return 0;
+}
diff --git a/example/Persistent_cohomology/persistence_from_file.cpp b/example/Persistent_cohomology/persistence_from_file.cpp
new file mode 100644
index 00000000..67235467
--- /dev/null
+++ b/example/Persistent_cohomology/persistence_from_file.cpp
@@ -0,0 +1,144 @@
+/* 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) 2014 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/>.
+ */
+
+#include <gudhi/reader_utils.h>
+#include <gudhi/graph_simplicial_complex.h>
+#include <gudhi/distance_functions.h>
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/Persistent_cohomology.h>
+
+#include <boost/program_options.hpp>
+
+#include <string>
+
+using namespace Gudhi;
+using namespace Gudhi::persistent_cohomology;
+
+typedef int Vertex_handle;
+typedef double Filtration_value;
+
+void program_options(int argc, char * argv[]
+ , std::string & simplex_tree_file
+ , std::string & output_file
+ , int & p
+ , Filtration_value & min_persistence);
+
+int main(int argc, char * argv[]) {
+ std::string simplex_tree_file;
+ std::string output_file;
+ int p;
+ Filtration_value min_persistence;
+
+ program_options(argc, argv, simplex_tree_file, output_file, p, min_persistence);
+
+ std::cout << "Simplex_tree from file=" << simplex_tree_file.c_str() << " - output_file=" << output_file.c_str()
+ << std::endl;
+ std::cout << " - p=" << p << " - min_persistence=" << min_persistence << std::endl;
+
+ // Read the list of simplices from a file.
+ Simplex_tree<> simplex_tree;
+
+ std::ifstream simplex_tree_stream(simplex_tree_file);
+ simplex_tree_stream >> simplex_tree;
+
+ std::cout << "The complex contains " << simplex_tree.num_simplices() << " simplices" << std::endl;
+ std::cout << " - dimension " << simplex_tree.dimension() << " - filtration " << simplex_tree.filtration()
+ << std::endl;
+
+ /*
+ std::cout << std::endl << std::endl << "Iterator on Simplices in the filtration, with [filtration value]:" << std::endl;
+ for( auto f_simplex : simplex_tree.filtration_simplex_range() )
+ { std::cout << " " << "[" << simplex_tree.filtration(f_simplex) << "] ";
+ for( auto vertex : simplex_tree.simplex_vertex_range(f_simplex) )
+ { std::cout << vertex << " "; }
+ std::cout << std::endl;
+ }*/
+
+ // Sort the simplices in the order of the filtration
+ simplex_tree.initialize_filtration();
+
+ // Compute the persistence diagram of the complex
+ Persistent_cohomology< Simplex_tree<>, Field_Zp > pcoh(simplex_tree);
+ // initializes the coefficient field for homology
+ pcoh.init_coefficients(p);
+
+ pcoh.compute_persistent_cohomology(min_persistence);
+
+ // Output the diagram in output_file
+ if (output_file.empty()) {
+ pcoh.output_diagram();
+ } else {
+ std::ofstream out(output_file);
+ pcoh.output_diagram(out);
+ out.close();
+ }
+
+ return 0;
+}
+
+void program_options(int argc, char * argv[]
+ , std::string & simplex_tree_file
+ , std::string & output_file
+ , int & p
+ , Filtration_value & min_persistence) {
+ namespace po = boost::program_options;
+ po::options_description hidden("Hidden options");
+ hidden.add_options()
+ ("input-file", po::value<std::string>(&simplex_tree_file),
+ "Name of file containing a simplex set. Format is one simplex per line (cf. reader_utils.h - read_simplex): Dim1 X11 X12 ... X1d Fil1 ");
+
+ po::options_description visible("Allowed options", 100);
+ visible.add_options()
+ ("help,h", "produce help message")
+ ("output-file,o", po::value<std::string>(&output_file)->default_value(std::string()),
+ "Name of file in which the persistence diagram is written. Default print in std::cout")
+ ("field-charac,p", po::value<int>(&p)->default_value(11),
+ "Characteristic p of the coefficient field Z/pZ for computing homology.")
+ ("min-persistence,m", po::value<Filtration_value>(&min_persistence),
+ "Minimal lifetime of homology feature to be recorded. Default is 0");
+
+ po::positional_options_description pos;
+ pos.add("input-file", 1);
+
+ po::options_description all;
+ all.add(visible).add(hidden);
+
+ po::variables_map vm;
+ po::store(po::command_line_parser(argc, argv).
+ options(all).positional(pos).run(), vm);
+ po::notify(vm);
+
+ if (vm.count("help") || !vm.count("input-file")) {
+ std::cout << std::endl;
+ std::cout << "Compute the persistent homology with coefficient field Z/pZ \n";
+ std::cout << "of a Rips complex defined on a set of input points.\n \n";
+ std::cout << "The output diagram contains one bar per line, written with the convention: \n";
+ std::cout << " p dim b d \n";
+ std::cout << "where dim is the dimension of the homological feature,\n";
+ std::cout << "b and d are respectively the birth and death of the feature and \n";
+ std::cout << "p is the characteristic of the field Z/pZ used for homology coefficients." << std::endl << std::endl;
+
+ std::cout << "Usage: " << argv[0] << " [options] input-file" << std::endl << std::endl;
+ std::cout << visible << std::endl;
+ std::abort();
+ }
+}
diff --git a/example/Persistent_cohomology/persistence_from_simple_simplex_tree.cpp b/example/Persistent_cohomology/persistence_from_simple_simplex_tree.cpp
new file mode 100644
index 00000000..ba772f04
--- /dev/null
+++ b/example/Persistent_cohomology/persistence_from_simple_simplex_tree.cpp
@@ -0,0 +1,178 @@
+/* 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) 2014 INRIA Sophia Antipolis-Méditerranée (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/>.
+ */
+
+#include <gudhi/graph_simplicial_complex.h>
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/Persistent_cohomology.h>
+
+#include <iostream>
+#include <ctime>
+#include <utility>
+#include <vector>
+
+using namespace Gudhi;
+using namespace Gudhi::persistent_cohomology;
+
+typedef std::vector< Vertex_handle > typeVectorVertex;
+typedef std::pair<typeVectorVertex, Filtration_value> typeSimplex;
+typedef std::pair< Simplex_tree<>::Simplex_handle, bool > typePairSimplexBool;
+typedef Simplex_tree<> typeST;
+
+void usage(char * const progName) {
+ std::cerr << "Usage: " << progName << " coeff_field_characteristic[integer > 0] min_persistence[float >= -1.0]\n";
+ exit(-1);
+}
+
+int main(int argc, char * const argv[]) {
+ // program args management
+ if (argc != 3) {
+ std::cerr << "Error: Number of arguments (" << argc << ") is not correct\n";
+ usage(argv[0]);
+ }
+
+ int coeff_field_characteristic = 0;
+ int returnedScanValue = sscanf(argv[1], "%d", &coeff_field_characteristic);
+ if ((returnedScanValue == EOF) || (coeff_field_characteristic <= 0)) {
+ std::cerr << "Error: " << argv[1] << " is not correct\n";
+ usage(argv[0]);
+ }
+
+ Filtration_value min_persistence = 0.0;
+ returnedScanValue = sscanf(argv[2], "%lf", &min_persistence);
+ if ((returnedScanValue == EOF) || (min_persistence < -1.0)) {
+ std::cerr << "Error: " << argv[2] << " is not correct\n";
+ usage(argv[0]);
+ }
+
+ // TEST OF INSERTION
+ std::cout << "********************************************************************" << std::endl;
+ std::cout << "TEST OF INSERTION" << std::endl;
+ typeST st;
+
+ // ++ FIRST
+ std::cout << " - INSERT (0,1,2)" << std::endl;
+ typeVectorVertex SimplexVector = {0, 1, 2};
+ st.insert_simplex_and_subfaces(SimplexVector, 0.3);
+
+ // ++ SECOND
+ std::cout << " - INSERT 3" << std::endl;
+ SimplexVector = {3};
+ st.insert_simplex_and_subfaces(SimplexVector, 0.1);
+
+ // ++ THIRD
+ std::cout << " - INSERT (0,3)" << std::endl;
+ SimplexVector = {0, 3};
+ st.insert_simplex_and_subfaces(SimplexVector, 0.2);
+
+ // ++ FOURTH
+ std::cout << " - INSERT (0,1) (already inserted)" << std::endl;
+ SimplexVector = {0, 1};
+ st.insert_simplex_and_subfaces(SimplexVector, 0.2);
+
+ // ++ FIFTH
+ std::cout << " - INSERT (3,4,5)" << std::endl;
+ SimplexVector = {3, 4, 5};
+ st.insert_simplex_and_subfaces(SimplexVector, 0.3);
+
+ // ++ SIXTH
+ std::cout << " - INSERT (0,1,6,7)" << std::endl;
+ SimplexVector = {0, 1, 6, 7};
+ st.insert_simplex_and_subfaces(SimplexVector, 0.4);
+
+ // ++ SEVENTH
+ std::cout << " - INSERT (4,5,8,9)" << std::endl;
+ SimplexVector = {4, 5, 8, 9};
+ st.insert_simplex_and_subfaces(SimplexVector, 0.4);
+
+ // ++ EIGHTH
+ std::cout << " - INSERT (9,10,11)" << std::endl;
+ SimplexVector = {9, 10, 11};
+ st.insert_simplex_and_subfaces(SimplexVector, 0.3);
+
+ // ++ NINETH
+ std::cout << " - INSERT (2,10,12)" << std::endl;
+ SimplexVector = {2, 10, 12};
+ st.insert_simplex_and_subfaces(SimplexVector, 0.3);
+
+ // ++ TENTH
+ std::cout << " - INSERT (11,6)" << std::endl;
+ SimplexVector = {6, 11};
+ st.insert_simplex_and_subfaces(SimplexVector, 0.2);
+
+ // ++ ELEVENTH
+ std::cout << " - INSERT (13,14,15)" << std::endl;
+ SimplexVector = {13, 14, 15};
+ st.insert_simplex_and_subfaces(SimplexVector, 0.25);
+
+ /* Inserted simplex: */
+ /* 1 6 */
+ /* o---o */
+ /* /X\7/ 4 2 */
+ /* o---o---o---o o */
+ /* 2 0 3\X/8\ 10 /X\ */
+ /* o---o---o---o */
+ /* 5 9\X/ 12 */
+ /* o---o */
+ /* 11 6 */
+ /* In other words: */
+ /* A facet [2,1,0] */
+ /* An edge [0,3] */
+ /* A facet [3,4,5] */
+ /* A cell [0,1,6,7] */
+ /* A cell [4,5,8,9] */
+ /* A facet [9,10,11] */
+ /* An edge [11,6] */
+ /* An edge [10,12,2] */
+
+ st.set_dimension(2);
+ st.set_filtration(0.4);
+
+ std::cout << "The complex contains " << st.num_simplices() << " simplices - " << st.num_vertices() << " vertices "
+ << std::endl;
+ std::cout << " - dimension " << st.dimension() << " - filtration " << st.filtration() << std::endl;
+ std::cout << std::endl << std::endl << "Iterator on Simplices in the filtration, with [filtration value]:"
+ << std::endl;
+ std::cout << "**************************************************************" << std::endl;
+ std::cout << "strict graph G { " << std::endl;
+
+ for (auto f_simplex : st.filtration_simplex_range()) {
+ std::cout << " " << "[" << st.filtration(f_simplex) << "] ";
+ for (auto vertex : st.simplex_vertex_range(f_simplex)) {
+ std::cout << static_cast<int>(vertex) << " -- ";
+ }
+ std::cout << ";" << std::endl;
+ }
+
+ std::cout << "}" << std::endl;
+ std::cout << "**************************************************************" << std::endl;
+
+ // Compute the persistence diagram of the complex
+ persistent_cohomology::Persistent_cohomology< Simplex_tree<>, Field_Zp > pcoh(st);
+ // initializes the coefficient field for homology
+ pcoh.init_coefficients(coeff_field_characteristic);
+
+ pcoh.compute_persistent_cohomology(min_persistence);
+
+ // Output the diagram in filediag
+ pcoh.output_diagram();
+ return 0;
+}
diff --git a/example/Persistent_cohomology/plain_homology.cpp b/example/Persistent_cohomology/plain_homology.cpp
new file mode 100644
index 00000000..ae82c817
--- /dev/null
+++ b/example/Persistent_cohomology/plain_homology.cpp
@@ -0,0 +1,95 @@
+/* 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): Marc Glisse
+ *
+ * Copyright (C) 2015 INRIA Saclay - Ile-de-France (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/>.
+ */
+
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/Persistent_cohomology.h>
+
+#include <iostream>
+#include <vector>
+#include <cstdint> // for std::uint8_t
+
+using namespace Gudhi;
+
+/* We could perfectly well use the default Simplex_tree<> (which uses
+ * Simplex_tree_options_full_featured), the following simply demonstrates
+ * how to save on storage by not storing a filtration value. */
+
+struct MyOptions : Simplex_tree_options_full_featured {
+ // Implicitly use 0 as filtration value for all simplices
+ static const bool store_filtration = false;
+ // The persistence algorithm needs this
+ static const bool store_key = true;
+ // I have few vertices
+ typedef short Vertex_handle;
+ // Maximum number of simplices to compute persistence is 2^8 - 1 = 255. One is reserved for null_key
+ typedef std::uint8_t Simplex_key;
+};
+typedef Simplex_tree<MyOptions> ST;
+
+int main() {
+ ST st;
+
+ /* Complex to build. */
+ /* 1 3 */
+ /* o---o */
+ /* /X\ / */
+ /* o---o o */
+ /* 2 0 4 */
+
+ const short triangle012[] = {0, 1, 2};
+ const short edge03[] = {0, 3};
+ const short edge13[] = {1, 3};
+ const short vertex4[] = {4};
+ st.insert_simplex_and_subfaces(triangle012);
+ st.insert_simplex_and_subfaces(edge03);
+ st.insert_simplex(edge13);
+ st.insert_simplex(vertex4);
+ // FIXME: Remove this line
+ st.set_dimension(2);
+
+ // Sort the simplices in the order of the filtration
+ st.initialize_filtration();
+
+ // Class for homology computation
+ persistent_cohomology::Persistent_cohomology<ST, persistent_cohomology::Field_Zp> pcoh(st);
+
+ // Initialize the coefficient field Z/2Z for homology
+ pcoh.init_coefficients(2);
+
+ // Compute the persistence diagram of the complex
+ pcoh.compute_persistent_cohomology();
+
+ // Print the result. The format is, on each line: 2 dim 0 inf
+ // where 2 represents the field, dim the dimension of the feature.
+ // 2 0 0 inf
+ // 2 0 0 inf
+ // 2 1 0 inf
+ // means that in Z/2Z-homology, the Betti numbers are b0=2 and b1=1.
+ pcoh.output_diagram();
+
+ // Print the Betti numbers are b0=2 and b1=1.
+ std::cout << std::endl;
+ std::cout << "The Betti numbers are : ";
+ for (int i = 0; i < st.dimension(); i++)
+ std::cout << "b" << i << " = " << pcoh.betti_number(i) << " ; ";
+ std::cout << std::endl;
+}
diff --git a/example/Persistent_cohomology/rips_multifield_persistence.cpp b/example/Persistent_cohomology/rips_multifield_persistence.cpp
new file mode 100644
index 00000000..c5cd775d
--- /dev/null
+++ b/example/Persistent_cohomology/rips_multifield_persistence.cpp
@@ -0,0 +1,158 @@
+/* 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): Clément Maria
+ *
+ * Copyright (C) 2014 INRIA Sophia Antipolis-Méditerranée (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/>.
+ */
+
+#include <gudhi/reader_utils.h>
+#include <gudhi/graph_simplicial_complex.h>
+#include <gudhi/distance_functions.h>
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/Persistent_cohomology.h>
+#include <gudhi/Persistent_cohomology/Multi_field.h>
+
+#include <boost/program_options.hpp>
+
+#include <string>
+#include <vector>
+
+using namespace Gudhi;
+using namespace Gudhi::persistent_cohomology;
+
+typedef int Vertex_handle;
+typedef double Filtration_value;
+
+void program_options(int argc, char * argv[]
+ , std::string & filepoints
+ , std::string & filediag
+ , Filtration_value & threshold
+ , int & dim_max
+ , int & min_p
+ , int & max_p
+ , Filtration_value & min_persistence);
+
+int main(int argc, char * argv[]) {
+ std::string filepoints;
+ std::string filediag;
+ Filtration_value threshold;
+ int dim_max;
+ int min_p;
+ int max_p;
+ Filtration_value min_persistence;
+
+ program_options(argc, argv, filepoints, filediag, threshold, dim_max, min_p, max_p, min_persistence);
+
+ // Extract the points from the file filepoints
+ typedef std::vector<double> Point_t;
+ std::vector< Point_t > points;
+ read_points(filepoints, points);
+
+ // Compute the proximity graph of the points
+ Graph_t prox_graph = compute_proximity_graph(points, threshold
+ , euclidean_distance<Point_t>);
+
+ // Construct the Rips complex in a Simplex Tree
+ typedef Simplex_tree<Simplex_tree_options_fast_persistence> ST;
+ ST st;
+ // insert the proximity graph in the simplex tree
+ st.insert_graph(prox_graph);
+ // expand the graph until dimension dim_max
+ st.expansion(dim_max);
+
+ // Sort the simplices in the order of the filtration
+ st.initialize_filtration();
+
+ // Compute the persistence diagram of the complex
+ Persistent_cohomology<ST, Multi_field > pcoh(st);
+ // initializes the coefficient field for homology
+ pcoh.init_coefficients(min_p, max_p);
+ // compute persistent homology, disgarding persistent features of life shorter than min_persistence
+ pcoh.compute_persistent_cohomology(min_persistence);
+
+ // Output the diagram in filediag
+ if (filediag.empty()) {
+ pcoh.output_diagram();
+ } else {
+ std::ofstream out(filediag);
+ pcoh.output_diagram(out);
+ out.close();
+ }
+
+ return 0;
+}
+
+void program_options(int argc, char * argv[]
+ , std::string & filepoints
+ , std::string & filediag
+ , Filtration_value & threshold
+ , int & dim_max
+ , int & min_p
+ , int & max_p
+ , Filtration_value & min_persistence) {
+ namespace po = boost::program_options;
+ po::options_description hidden("Hidden options");
+ hidden.add_options()
+ ("input-file", po::value<std::string>(&filepoints),
+ "Name of file containing a point set. Format is one point per line: X1 ... Xd \n");
+
+ po::options_description visible("Allowed options");
+ visible.add_options()
+ ("help,h", "produce help message")
+ ("output-file,o", po::value<std::string>(&filediag)->default_value(std::string()),
+ "Name of file in which the persistence diagram is written. Default print in std::cout")
+ ("max-edge-length,r", po::value<Filtration_value>(&threshold)->default_value(0),
+ "Maximal length of an edge for the Rips complex construction.")
+ ("cpx-dimension,d", po::value<int>(&dim_max)->default_value(1),
+ "Maximal dimension of the Rips complex we want to compute.")
+ ("min-field-charac,p", po::value<int>(&min_p)->default_value(2),
+ "Minimal characteristic p of the coefficient field Z/pZ.")
+ ("max-field-charac,q", po::value<int>(&max_p)->default_value(1223),
+ "Minimial characteristic q of the coefficient field Z/pZ.")
+ ("min-persistence,m", po::value<Filtration_value>(&min_persistence),
+ "Minimal lifetime of homology feature to be recorded. Default is 0");
+
+ po::positional_options_description pos;
+ pos.add("input-file", 1);
+
+ po::options_description all;
+ all.add(visible).add(hidden);
+
+ po::variables_map vm;
+ po::store(po::command_line_parser(argc, argv).
+ options(all).positional(pos).run(), vm);
+ po::notify(vm);
+
+ if (vm.count("help") || !vm.count("input-file")) {
+ std::cout << std::endl;
+ std::cout << "Compute the persistent homology with various coefficient fields \n";
+ std::cout << "of a Rips complex defined on a set of input points. The coefficient \n";
+ std::cout << "fields are all the Z/rZ for a prime number r contained in the \n";
+ std::cout << "specified range [p,q]\n \n";
+ std::cout << "The output diagram contains one bar per line, written with the convention: \n";
+ std::cout << " p1*...*pr dim b d \n";
+ std::cout << "where dim is the dimension of the homological feature,\n";
+ std::cout << "b and d are respectively the birth and death of the feature and \n";
+ std::cout << "p1*...*pr is the product of prime numbers pi such that the homology \n";
+ std::cout << "feature exists in homology with Z/piZ coefficients." << std::endl << std::endl;
+
+ std::cout << "Usage: " << argv[0] << " [options] input-file" << std::endl << std::endl;
+ std::cout << visible << std::endl;
+ std::abort();
+ }
+}
diff --git a/example/Persistent_cohomology/rips_persistence.cpp b/example/Persistent_cohomology/rips_persistence.cpp
new file mode 100644
index 00000000..cab49395
--- /dev/null
+++ b/example/Persistent_cohomology/rips_persistence.cpp
@@ -0,0 +1,153 @@
+/* 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): Clément Maria
+ *
+ * Copyright (C) 2014 INRIA Sophia Antipolis-Méditerranée (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/>.
+ */
+
+#include <gudhi/reader_utils.h>
+#include <gudhi/graph_simplicial_complex.h>
+#include <gudhi/distance_functions.h>
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/Persistent_cohomology.h>
+
+#include <boost/program_options.hpp>
+
+#include <string>
+#include <vector>
+#include <limits> // infinity
+
+using namespace Gudhi;
+using namespace Gudhi::persistent_cohomology;
+
+typedef int Vertex_handle;
+typedef double Filtration_value;
+
+void program_options(int argc, char * argv[]
+ , std::string & filepoints
+ , std::string & filediag
+ , Filtration_value & threshold
+ , int & dim_max
+ , int & p
+ , Filtration_value & min_persistence);
+
+int main(int argc, char * argv[]) {
+ std::string filepoints;
+ std::string filediag;
+ Filtration_value threshold;
+ int dim_max;
+ int p;
+ Filtration_value min_persistence;
+
+ program_options(argc, argv, filepoints, filediag, threshold, dim_max, p, min_persistence);
+
+ // Extract the points from the file filepoints
+ typedef std::vector<double> Point_t;
+ std::vector< Point_t > points;
+ read_points(filepoints, points);
+
+ // Compute the proximity graph of the points
+ Graph_t prox_graph = compute_proximity_graph(points, threshold
+ , euclidean_distance<Point_t>);
+
+ // Construct the Rips complex in a Simplex Tree
+ typedef Simplex_tree<Simplex_tree_options_fast_persistence> ST;
+ ST st;
+ // insert the proximity graph in the simplex tree
+ st.insert_graph(prox_graph);
+ // expand the graph until dimension dim_max
+ st.expansion(dim_max);
+
+ std::cout << "The complex contains " << st.num_simplices() << " simplices \n";
+ std::cout << " and has dimension " << st.dimension() << " \n";
+
+ // Sort the simplices in the order of the filtration
+ st.initialize_filtration();
+
+ // Compute the persistence diagram of the complex
+ persistent_cohomology::Persistent_cohomology<ST, Field_Zp > pcoh(st);
+ // initializes the coefficient field for homology
+ pcoh.init_coefficients(p);
+
+ pcoh.compute_persistent_cohomology(min_persistence);
+
+ // Output the diagram in filediag
+ if (filediag.empty()) {
+ pcoh.output_diagram();
+ } else {
+ std::ofstream out(filediag);
+ pcoh.output_diagram(out);
+ out.close();
+ }
+
+ return 0;
+}
+
+void program_options(int argc, char * argv[]
+ , std::string & filepoints
+ , std::string & filediag
+ , Filtration_value & threshold
+ , int & dim_max
+ , int & p
+ , Filtration_value & min_persistence) {
+ namespace po = boost::program_options;
+ po::options_description hidden("Hidden options");
+ hidden.add_options()
+ ("input-file", po::value<std::string>(&filepoints),
+ "Name of file containing a point set. Format is one point per line: X1 ... Xd ");
+
+ po::options_description visible("Allowed options", 100);
+ visible.add_options()
+ ("help,h", "produce help message")
+ ("output-file,o", po::value<std::string>(&filediag)->default_value(std::string()),
+ "Name of file in which the persistence diagram is written. Default print in std::cout")
+ ("max-edge-length,r", po::value<Filtration_value>(&threshold)->default_value(std::numeric_limits<Filtration_value>::infinity()),
+ "Maximal length of an edge for the Rips complex construction.")
+ ("cpx-dimension,d", po::value<int>(&dim_max)->default_value(1),
+ "Maximal dimension of the Rips complex we want to compute.")
+ ("field-charac,p", po::value<int>(&p)->default_value(11),
+ "Characteristic p of the coefficient field Z/pZ for computing homology.")
+ ("min-persistence,m", po::value<Filtration_value>(&min_persistence),
+ "Minimal lifetime of homology feature to be recorded. Default is 0. Enter a negative value to see zero length intervals");
+
+ po::positional_options_description pos;
+ pos.add("input-file", 1);
+
+ po::options_description all;
+ all.add(visible).add(hidden);
+
+ po::variables_map vm;
+ po::store(po::command_line_parser(argc, argv).
+ options(all).positional(pos).run(), vm);
+ po::notify(vm);
+
+ if (vm.count("help") || !vm.count("input-file")) {
+ std::cout << std::endl;
+ std::cout << "Compute the persistent homology with coefficient field Z/pZ \n";
+ std::cout << "of a Rips complex defined on a set of input points.\n \n";
+ std::cout << "The output diagram contains one bar per line, written with the convention: \n";
+ std::cout << " p dim b d \n";
+ std::cout << "where dim is the dimension of the homological feature,\n";
+ std::cout << "b and d are respectively the birth and death of the feature and \n";
+ std::cout << "p is the characteristic of the field Z/pZ used for homology coefficients." << std::endl << std::endl;
+
+ std::cout << "Usage: " << argv[0] << " [options] input-file" << std::endl << std::endl;
+ std::cout << visible << std::endl;
+ std::abort();
+ }
+}
diff --git a/example/Persistent_cohomology/rips_persistence_via_boundary_matrix.cpp b/example/Persistent_cohomology/rips_persistence_via_boundary_matrix.cpp
new file mode 100644
index 00000000..4c6656f5
--- /dev/null
+++ b/example/Persistent_cohomology/rips_persistence_via_boundary_matrix.cpp
@@ -0,0 +1,180 @@
+/* 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): Clément Maria, Marc Glisse
+ *
+ * Copyright (C) 2014 INRIA Sophia Antipolis-Méditerranée (France),
+ * 2015 INRIA Saclay Île de 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/>.
+ */
+
+#include <gudhi/reader_utils.h>
+#include <gudhi/graph_simplicial_complex.h>
+#include <gudhi/distance_functions.h>
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/Persistent_cohomology.h>
+#include <gudhi/Hasse_complex.h>
+
+#include <boost/program_options.hpp>
+
+#ifdef GUDHI_USE_TBB
+#include <tbb/task_scheduler_init.h>
+#endif
+
+#include <string>
+#include <vector>
+
+////////////////////////////////////////////////////////////////
+// //
+// WARNING: persistence computation itself is not parallel, //
+// and this uses more memory than rips_persistence. //
+// //
+////////////////////////////////////////////////////////////////
+
+using namespace Gudhi;
+using namespace Gudhi::persistent_cohomology;
+
+typedef int Vertex_handle;
+typedef double Filtration_value;
+
+void program_options(int argc, char * argv[]
+ , std::string & filepoints
+ , std::string & filediag
+ , Filtration_value & threshold
+ , int & dim_max
+ , int & p
+ , Filtration_value & min_persistence);
+
+int main(int argc, char * argv[]) {
+ std::string filepoints;
+ std::string filediag;
+ Filtration_value threshold;
+ int dim_max;
+ int p;
+ Filtration_value min_persistence;
+
+ program_options(argc, argv, filepoints, filediag, threshold, dim_max, p, min_persistence);
+
+ // Extract the points from the file filepoints
+ typedef std::vector<double> Point_t;
+ std::vector< Point_t > points;
+ read_points(filepoints, points);
+
+ // Compute the proximity graph of the points
+ Graph_t prox_graph = compute_proximity_graph(points, threshold
+ , euclidean_distance<Point_t>);
+
+ // Construct the Rips complex in a Simplex Tree
+ Simplex_tree<>& st = *new Simplex_tree<>;
+ // insert the proximity graph in the simplex tree
+ st.insert_graph(prox_graph);
+ // expand the graph until dimension dim_max
+ st.expansion(dim_max);
+
+ std::cout << "The complex contains " << st.num_simplices() << " simplices \n";
+ std::cout << " and has dimension " << st.dimension() << " \n";
+
+#ifdef GUDHI_USE_TBB
+ // Unnecessary, but clarifies which operations are parallel.
+ tbb::task_scheduler_init ts;
+#endif
+
+ // Sort the simplices in the order of the filtration
+ st.initialize_filtration();
+ int count = 0;
+ for (auto sh : st.filtration_simplex_range())
+ st.assign_key(sh, count++);
+
+ // Convert to a more convenient representation.
+ Hasse_complex<> hcpx(st);
+
+#ifdef GUDHI_USE_TBB
+ ts.terminate();
+#endif
+
+ // Free some space.
+ delete &st;
+
+ // Compute the persistence diagram of the complex
+ persistent_cohomology::Persistent_cohomology< Hasse_complex<>, Field_Zp > pcoh(hcpx);
+ // initializes the coefficient field for homology
+ pcoh.init_coefficients(p);
+
+ pcoh.compute_persistent_cohomology(min_persistence);
+
+ // Output the diagram in filediag
+ if (filediag.empty()) {
+ pcoh.output_diagram();
+ } else {
+ std::ofstream out(filediag);
+ pcoh.output_diagram(out);
+ out.close();
+ }
+}
+
+void program_options(int argc, char * argv[]
+ , std::string & filepoints
+ , std::string & filediag
+ , Filtration_value & threshold
+ , int & dim_max
+ , int & p
+ , Filtration_value & min_persistence) {
+ namespace po = boost::program_options;
+ po::options_description hidden("Hidden options");
+ hidden.add_options()
+ ("input-file", po::value<std::string>(&filepoints),
+ "Name of file containing a point set. Format is one point per line: X1 ... Xd ");
+
+ po::options_description visible("Allowed options", 100);
+ visible.add_options()
+ ("help,h", "produce help message")
+ ("output-file,o", po::value<std::string>(&filediag)->default_value(std::string()),
+ "Name of file in which the persistence diagram is written. Default print in std::cout")
+ ("max-edge-length,r", po::value<Filtration_value>(&threshold)->default_value(0),
+ "Maximal length of an edge for the Rips complex construction.")
+ ("cpx-dimension,d", po::value<int>(&dim_max)->default_value(1),
+ "Maximal dimension of the Rips complex we want to compute.")
+ ("field-charac,p", po::value<int>(&p)->default_value(11),
+ "Characteristic p of the coefficient field Z/pZ for computing homology.")
+ ("min-persistence,m", po::value<Filtration_value>(&min_persistence),
+ "Minimal lifetime of homology feature to be recorded. Default is 0. Enter a negative value to see zero length intervals");
+
+ po::positional_options_description pos;
+ pos.add("input-file", 1);
+
+ po::options_description all;
+ all.add(visible).add(hidden);
+
+ po::variables_map vm;
+ po::store(po::command_line_parser(argc, argv).
+ options(all).positional(pos).run(), vm);
+ po::notify(vm);
+
+ if (vm.count("help") || !vm.count("input-file")) {
+ std::cout << std::endl;
+ std::cout << "Compute the persistent homology with coefficient field Z/pZ \n";
+ std::cout << "of a Rips complex defined on a set of input points.\n \n";
+ std::cout << "The output diagram contains one bar per line, written with the convention: \n";
+ std::cout << " p dim b d \n";
+ std::cout << "where dim is the dimension of the homological feature,\n";
+ std::cout << "b and d are respectively the birth and death of the feature and \n";
+ std::cout << "p is the characteristic of the field Z/pZ used for homology coefficients." << std::endl << std::endl;
+
+ std::cout << "Usage: " << argv[0] << " [options] input-file" << std::endl << std::endl;
+ std::cout << visible << std::endl;
+ std::abort();
+ }
+}