Make it possible to select active subrotamer in flexible rotamer model

The active rotamer controls which subrotamer is used when the
ApplyOnResidue function gets called

sidechain/doc/rotamer.rst

@@ -437,6 +437,17 @@ Rotamers
 
     :type indices:      :class:`list`
 
+  .. method:: SetActiveSubrotamer(idx)
+
+    The provided **idx** relates to the subrotamer definitions added at the
+    rotamer buildup. This idx controls which subrotamer is used when
+    :func:`ApplyOnResidue` gets called. By default, the value is 0
+    => first added subrotamer definition gets used.
+
+    :param idx:         Index of subrotamer definition applied on residues
+
+    :type idx:          :class:`int`
+
 
   .. method:: SetTemperature(temperature)
 

sidechain/pymod/export_rotamer.cc

@@ -179,6 +179,7 @@ void export_Rotamer()
     .def("__getitem__",&WrapFRMGetItem,arg("index"))
     .def("GetNumSubrotamers",&FRMRotamer::subrotamer_size)
     .def("GetSubrotamerDefinition",&WrapGetSubrotamerDefinition, (arg("index")))
+    .def("SetActiveSubrotamer", &FRMRotamer::SetActiveSubrotamer, (arg("idx")))
     .def("ApplyOnResidue", WrapFRMApplyOnRes,
          (arg("res"), arg("consider_hydrogens")=false, arg("new_res_name")=""))
     .def("ApplyOnResidue", WrapFRMApplyOnResAA,

sidechain/src/rotamer.cc

@@ -58,8 +58,8 @@ void RRMRotamer::ApplyOnResidue(loop::AllAtomPositions& all_atom,
 FRMRotamer::FRMRotamer(const std::vector<Particle>& particles, Real T, 
                        Real probability, Real internal_e_prefactor):
                        particles_(particles), n_particles_(particles.size()),
-                       internal_energy_(0.0),frame_energy_(0.0), 
-                       T_(T), probability_(probability),
+                       active_subrotamer_(0), internal_energy_(0.0),
+                       frame_energy_(0.0), T_(T), probability_(probability),
                        internal_e_prefactor_(internal_e_prefactor){
   subrotamer_associations_.resize(n_particles_,std::vector<int>());
 }
@@ -74,6 +74,13 @@ void FRMRotamer::AddSubrotamerDefinition(const std::vector<int>& definition){
   frame_energies_.push_back(0.0);
 }
 
+void FRMRotamer::SetActiveSubrotamer(uint idx) {
+  if(idx >= subrotamer_definitions_.size()){
+    throw promod3::Error("Invalid subrotamer idx provided!");
+  }
+  active_subrotamer_ = idx;
+}
+
 void FRMRotamer::ApplyOnResidue(ost::mol::ResidueHandle& res,
                                 bool consider_hydrogens,
                                 const String& new_res_name) const {
@@ -88,7 +95,7 @@ void FRMRotamer::ApplyOnResidue(ost::mol::ResidueHandle& res,
 
   ost::mol::XCSEditor ed = res.GetEntity().EditXCS(ost::mol::BUFFERED_EDIT);
 
-  const std::vector<int>& sub_def = subrotamer_definitions_[0];
+  const std::vector<int>& sub_def = subrotamer_definitions_[active_subrotamer_];
   ost::mol::AtomHandle a;
   for (uint i = 0; i < sub_def.size(); ++i) {
     const Particle& p=particles_[sub_def[i]];
@@ -123,7 +130,7 @@ void FRMRotamer::ApplyOnResidue(loop::AllAtomPositions& all_atom,
   // check res_idx
   all_atom.CheckResidueIndex(res_idx);
   // reset all heavy atoms
-  const std::vector<int>& sub_def_ = subrotamer_definitions_[0];
+  const std::vector<int>& sub_def_ = subrotamer_definitions_[active_subrotamer_];
   for (uint i = 0; i < sub_def_.size(); ++i) {
     const Particle& p = particles_[sub_def_[i]];
     const String& particle_name = p.GetName();

sidechain/src/rotamer.hh

@@ -99,6 +99,8 @@ public:
 
   void AddSubrotamerDefinition(const std::vector<int>& definition);
 
+  void SetActiveSubrotamer(uint idx);
+
   Real GetInternalEnergyPrefactor() const { return internal_e_prefactor_; }
 
   Real GetInternalEnergy() const { return internal_energy_; }
@@ -190,6 +192,7 @@ private:
   size_t n_particles_;
   std::vector<std::vector<int> > subrotamer_definitions_;
   std::vector<std::vector<int> > subrotamer_associations_;
+  uint active_subrotamer_;
   Real internal_energy_;
   Real frame_energy_;
   std::vector<Real> frame_energies_;