git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/kernels@3970 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: 161d2d6200b09ba799dbb3694be6c7afe353abb5

1 files changed, 12 insertions, 7 deletions

diff --git a/src/Persistence_representations/include/gudhi/Sliced_Wasserstein.h b/src/Persistence_representations/include/gudhi/Sliced_Wasserstein.h
index a0191dd7..8fc4bd15 100644
--- a/src/Persistence_representations/include/gudhi/Sliced_Wasserstein.h
+++ b/src/Persistence_representations/include/gudhi/Sliced_Wasserstein.h
@@ -150,24 +150,29 @@ class Sliced_Wasserstein {
     if(this->approx == -1){
 
       // Add projections onto diagonal.
-      int n1, n2; n1 = diagram1.size(); n2 = diagram2.size(); double max_ordinate = 0; double max_abscissa = 0;
+      int n1, n2; n1 = diagram1.size(); n2 = diagram2.size();
+      double min_ordinate = std::numeric_limits<double>::max();    double min_abscissa = std::numeric_limits<double>::max();
+      double max_ordinate = std::numeric_limits<double>::lowest(); double max_abscissa = std::numeric_limits<double>::lowest();
       for (int i = 0; i < n2; i++){
-        max_ordinate = std::max(max_ordinate, std::abs(diagram2[i].second)); max_abscissa = std::max(max_abscissa, std::abs(diagram2[i].first));
+        min_ordinate = std::min(min_ordinate, diagram2[i].second); min_abscissa = std::min(min_abscissa, diagram2[i].first);
+        max_ordinate = std::max(max_ordinate, diagram2[i].second); max_abscissa = std::max(max_abscissa, diagram2[i].first);
         diagram1.emplace_back(  (diagram2[i].first+diagram2[i].second)/2, (diagram2[i].first+diagram2[i].second)/2  );
       }
       for (int i = 0; i < n1; i++){
-        max_ordinate = std::max(max_ordinate, std::abs(diagram1[i].second)); max_abscissa = std::max(max_abscissa, std::abs(diagram1[i].first));
+        min_ordinate = std::min(min_ordinate, diagram1[i].second); min_abscissa = std::min(min_abscissa, diagram1[i].first);
+        max_ordinate = std::max(max_ordinate, diagram1[i].second); max_abscissa = std::max(max_abscissa, diagram1[i].first);
         diagram2.emplace_back(  (diagram1[i].first+diagram1[i].second)/2, (diagram1[i].first+diagram1[i].second)/2  );
       }
       int num_pts_dgm = diagram1.size();
 
       // Slightly perturb the points so that the PDs are in generic positions.
-      double thresh_y = max_ordinate * 0.00001; double thresh_x = max_abscissa * 0.00001;
+      double epsilon = 0.0001;
+      double thresh_y = (max_ordinate-min_ordinate) * epsilon; double thresh_x = (max_abscissa-min_abscissa) * epsilon;
       std::random_device rd; std::default_random_engine re(rd()); std::uniform_real_distribution<double> uni(-1,1);
-      double epsilon = uni(re);
       for (int i = 0; i < num_pts_dgm; i++){
-        diagram1[i].first += thresh_x*epsilon; diagram1[i].second += thresh_y*epsilon;
-        diagram2[i].first += thresh_x*epsilon; diagram2[i].second += thresh_y*epsilon;
+        double u = uni(re);
+        diagram1[i].first += u*thresh_x; diagram1[i].second += u*thresh_y;
+        diagram2[i].first += u*thresh_x; diagram2[i].second += u*thresh_y;
       }
 
       // Compute all angles in both PDs.