Split compute_persistence from get_persistence.

1 files changed, 16 insertions, 13 deletions

diff --git a/src/python/include/Persistent_cohomology_interface.h b/src/python/include/Persistent_cohomology_interface.h
index 8c79e6f3..a29ebbee 100644
--- a/src/python/include/Persistent_cohomology_interface.h
+++ b/src/python/include/Persistent_cohomology_interface.h
@@ -23,6 +23,7 @@ template<class FilteredComplex>
 class Persistent_cohomology_interface : public
 persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomology::Field_Zp> {
  private:
+   typedef persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomology::Field_Zp> Base;
   /*
    * Compare two intervals by dimension, then by length.
    */
@@ -43,25 +44,28 @@ persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomol
 
  public:
   Persistent_cohomology_interface(FilteredComplex* stptr)
-      : persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomology::Field_Zp>(*stptr),
+      : Base(*stptr),
       stptr_(stptr) { }
 
   Persistent_cohomology_interface(FilteredComplex* stptr, bool persistence_dim_max)
-      : persistent_cohomology::Persistent_cohomology<FilteredComplex,
-          persistent_cohomology::Field_Zp>(*stptr, persistence_dim_max),
+      : Base(*stptr, persistence_dim_max),
         stptr_(stptr) { }
 
-  std::vector<std::pair<int, std::pair<double, double>>> get_persistence(int homology_coeff_field,
-                                                                         double min_persistence) {
-    persistent_cohomology::Persistent_cohomology<FilteredComplex,
-      persistent_cohomology::Field_Zp>::init_coefficients(homology_coeff_field);
-    persistent_cohomology::Persistent_cohomology<FilteredComplex,
-      persistent_cohomology::Field_Zp>::compute_persistent_cohomology(min_persistence);
+  void compute_persistence(int homology_coeff_field, double min_persistence) {
+    Base::init_coefficients(homology_coeff_field);
+    Base::compute_persistent_cohomology(min_persistence);
+  }
+
+  void maybe_compute_persistence(int homology_coeff_field, double min_persistence) {
+    // Currently get_persistent_pairs safely returns an empty vector before compute_persistent_cohomology
+    if(Base::get_persistent_pairs().empty())
+      compute_persistence(homology_coeff_field, min_persistence);
+  }
 
+  std::vector<std::pair<int, std::pair<double, double>>> get_persistence() {
     // Custom sort and output persistence
     cmp_intervals_by_dim_then_length cmp(stptr_);
-    auto persistent_pairs = persistent_cohomology::Persistent_cohomology<FilteredComplex,
-      persistent_cohomology::Field_Zp>::get_persistent_pairs();
+    auto persistent_pairs = Base::get_persistent_pairs();
     std::sort(std::begin(persistent_pairs), std::end(persistent_pairs), cmp);
 
     std::vector<std::pair<int, std::pair<double, double>>> persistence;
@@ -74,8 +78,7 @@ persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomol
   }
 
   std::vector<std::pair<std::vector<int>, std::vector<int>>> persistence_pairs() {
-    auto pairs = persistent_cohomology::Persistent_cohomology<FilteredComplex,
-      persistent_cohomology::Field_Zp>::get_persistent_pairs();
+    auto pairs = Base::get_persistent_pairs();
 
     std::vector<std::pair<std::vector<int>, std::vector<int>>> persistence_pairs;
     persistence_pairs.reserve(pairs.size());