1 files changed, 72 insertions, 0 deletions
diff --git a/src/Persistence_representations/utilities/persistence_landscapes/compute_scalar_product_of_landscapes.cpp b/src/Persistence_representations/utilities/persistence_landscapes/compute_scalar_product_of_landscapes.cpp
new file mode 100644
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--- /dev/null
+++ b/src/Persistence_representations/utilities/persistence_landscapes/compute_scalar_product_of_landscapes.cpp
@@ -0,0 +1,72 @@
+/*    This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+ *    See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+ *    Author(s):       Pawel Dlotko
+ *
+ *    Copyright (C) 2016 Inria
+ *
+ *    Modification(s):
+ *      - YYYY/MM Author: Description of the modification
+ */
+
+#include <gudhi/Persistence_landscape.h>
+
+#include <iostream>
+#include <sstream>
+#include <vector>
+
+using Persistence_landscape = Gudhi::Persistence_representations::Persistence_landscape;
+
+int main(int argc, char** argv) {
+  std::cout << "This program computes scalar product of persistence landscapes stored in a file (the file needs to be "
+            << "created beforehand). \n"
+            << "The parameters of this programs are names of files with persistence landscapes.\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<Persistence_landscape> landscaspes;
+  landscaspes.reserve(filenames.size());
+  for (size_t file_no = 0; file_no != filenames.size(); ++file_no) {
+    Persistence_landscape l;
+    l.load_landscape_from_file(filenames[file_no]);
+    landscaspes.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 != landscaspes.size(); ++i) {
+    for (size_t j = i; j != landscaspes.size(); ++j) {
+      scalar_product[i][j] = scalar_product[j][i] = compute_inner_product(landscaspes[i], landscaspes[j]);
+    }
+  }
+
+  // and now output the result to the screen and a file:
+  std::ofstream out;
+  out.open("scalar_product.land");
+  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.land' file\n";
+  return 0;
+}