reset_filtration from a dimension (instead of 'until')

2 files changed, 27 insertions, 18 deletions

diff --git a/src/Simplex_tree/include/gudhi/Simplex_tree.h b/src/Simplex_tree/include/gudhi/Simplex_tree.h
index adc8e801..89b4a5df 100644
--- a/src/Simplex_tree/include/gudhi/Simplex_tree.h
+++ b/src/Simplex_tree/include/gudhi/Simplex_tree.h
@@ -1668,31 +1668,36 @@ class Simplex_tree {
   }
 
  public:
-  /** \brief This function resets filtration value until a given dimension.
+  /** \brief This function resets filtration value from a given dimension. Resets all the Simplex_tree when
+   * `min_dim = 0`.
    * @param[in] filt_value The new filtration value.
-   * @param[in] max_dim The maximal dimension.
+   * @param[in] min_dim The minimal dimension.
    */
-  void reset_filtration(Filtration_value filt_value, int max_dim) {
+  void reset_filtration(Filtration_value filt_value, int min_dim) {
     for (auto& simplex : root_.members()) {
-      simplex.second.assign_filtration(filt_value);
-      if (has_children(&simplex) && max_dim > 0) {
-        rec_reset_filtration(simplex.second.children(), filt_value, (max_dim - 1));
+      if (min_dim <= 0) {
+        simplex.second.assign_filtration(filt_value);
+      }
+      if (has_children(&simplex)) {
+        rec_reset_filtration(simplex.second.children(), filt_value, min_dim);
       }
     }
     clear_filtration(); // Drop the cache.
   }
 
  private:
-  /** \brief Recursively resets filtration value until a given dimension.
+  /** \brief Recursively resets filtration value from a given dimension.
    * @param[in] sib Siblings to be parsed.
    * @param[in] filt_value The new filtration value.
-   * @param[in] max_dim The maximal dimension.
+   * @param[in] min_dim The maximal dimension.
    */
-  void rec_reset_filtration(Siblings * sib, Filtration_value filt_value, int max_dim) {
-    for (auto& simplex : sib->members()) {
-      simplex.second.assign_filtration(filt_value);
-      if (has_children(&simplex) && max_dim > 0) {
-        rec_reset_filtration(simplex.second.children(), filt_value, (max_dim - 1));
+  void rec_reset_filtration(Siblings * sib, Filtration_value filt_value, int min_dim) {
+    for (auto sh = sib->members().begin(); sh != sib->members().end(); ++sh) {
+      if (min_dim <= dimension(sh)) {
+        sh->second.assign_filtration(filt_value);
+      }
+      if (has_children(sh)) {
+        rec_reset_filtration(sh->second.children(), filt_value, min_dim);
       }
     }
   }
diff --git a/src/Simplex_tree/test/simplex_tree_unit_test.cpp b/src/Simplex_tree/test/simplex_tree_unit_test.cpp
index 9780f5b0..bdd41d34 100644
--- a/src/Simplex_tree/test/simplex_tree_unit_test.cpp
+++ b/src/Simplex_tree/test/simplex_tree_unit_test.cpp
@@ -965,21 +965,25 @@ BOOST_AUTO_TEST_CASE_TEMPLATE(simplex_tree_reset_filtration, typeST, list_of_tes
     for (auto vertex : st.simplex_vertex_range(f_simplex)) {
       std::clog << vertex << ",";
     }
-    std::clog << ") - filtration =" << st.filtration(f_simplex) << std::endl;
+    std::clog << ") - filtration = " << st.filtration(f_simplex);
+    std::clog << " - dimension = " << st.dimension(f_simplex) << std::endl;
+    // Guaranteed by construction
     BOOST_CHECK(st.filtration(f_simplex) >= 2.);
   }
 
   // dimension until 5 even if simplex tree is of dimension 3 to test the limits
-  for(int dimension = 0; dimension < 6; dimension ++) {
+  for(int dimension = 5; dimension >= 0; dimension --) {
+    std::clog << "### reset_filtration - dimension = " << dimension << "\n";
     st.reset_filtration(0., dimension);
     for (auto f_simplex : st.skeleton_simplex_range(3)) {
       std::clog << "vertex = (";
       for (auto vertex : st.simplex_vertex_range(f_simplex)) {
         std::clog << vertex << ",";
       }
-      std::clog << ") - filtration =" << st.filtration(f_simplex) << std::endl;
-      if (st.dimension(f_simplex) > dimension)
-        BOOST_CHECK(st.filtration(f_simplex) >= 1.);
+      std::clog << ") - filtration = " << st.filtration(f_simplex);
+      std::clog << " - dimension = " << st.dimension(f_simplex) << std::endl;
+      if (st.dimension(f_simplex) < dimension)
+        BOOST_CHECK(st.filtration(f_simplex) >= 2.);
       else
         BOOST_CHECK(st.filtration(f_simplex) == 0.);
     }