1 files changed, 86 insertions, 0 deletions
diff --git a/utilities/Persistence_representations/persistence_vectors/compute_scalar_product_of_persistence_vectors.cpp b/utilities/Persistence_representations/persistence_vectors/compute_scalar_product_of_persistence_vectors.cpp
new file mode 100644
index 00000000..303c6e3e
--- /dev/null
+++ b/utilities/Persistence_representations/persistence_vectors/compute_scalar_product_of_persistence_vectors.cpp
@@ -0,0 +1,86 @@
+/*    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):       Pawel Dlotko
+ *
+ *    Copyright (C) 2016  INRIA (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/Persistence_vectors.h>
+
+#include <iostream>
+#include <sstream>
+#include <limits>
+#include <vector>
+
+using Euclidean_distance = Gudhi::Euclidean_distance;
+using Vector_distances_in_diagram = Gudhi::Persistence_representations::Vector_distances_in_diagram<Euclidean_distance>;
+
+int main(int argc, char** argv) {
+  std::cout << "This program computes scalar product of persistence vectors stored in a file (the file needs to "
+            << "be created beforehand). \n"
+            << "The parameters of this programs are names of files with persistence vectors.\n";
+
+  if (argc < 3) {
+    std::cout << "Wrong number of parameters, the program will now terminate \n";
+    return 1;
+  }
+
+  std::vector<const char*> filenames;
+  for (int i = 1; i < argc; ++i) {
+    filenames.push_back(argv[i]);
+  }
+  std::vector<Vector_distances_in_diagram> vectors;
+  vectors.reserve(filenames.size());
+  for (size_t file_no = 0; file_no != filenames.size(); ++file_no) {
+    Vector_distances_in_diagram l;
+    l.load_from_file(filenames[file_no]);
+    vectors.push_back(l);
+  }
+
+  // and now we will compute the scalar product of landscapes.
+
+  // first we prepare an array:
+  std::vector<std::vector<double> > scalar_product(filenames.size());
+  for (size_t i = 0; i != filenames.size(); ++i) {
+    std::vector<double> v(filenames.size(), 0);
+    scalar_product[i] = v;
+  }
+
+  // and now we can compute the scalar product:
+  for (size_t i = 0; i != vectors.size(); ++i) {
+    for (size_t j = i; j != vectors.size(); ++j) {
+      scalar_product[i][j] = scalar_product[j][i] = vectors[i].compute_scalar_product(vectors[j]);
+    }
+  }
+
+  // and now output the result to the screen and a file:
+  std::ofstream out;
+  out.open("scalar_product.vect");
+  for (size_t i = 0; i != scalar_product.size(); ++i) {
+    for (size_t j = 0; j != scalar_product.size(); ++j) {
+      std::cout << scalar_product[i][j] << " ";
+      out << scalar_product[i][j] << " ";
+    }
+    std::cout << std::endl;
+    out << std::endl;
+  }
+  out.close();
+
+  std::cout << "Distance can be found in 'scalar_product.vect' file\n";
+  return 0;
+}