ProteinKinematics.h

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/**
 * \file IMP/kinematics/ProteinKinematics.h
 * \brief functionality for defining a kinematic forest for proteins
 *
 * Copyright 2007-2016 IMP Inventors. All rights reserved.
 *  \authors Dina Schneidman, Barak Raveh
 *
 */

#ifndef IMPKINEMATICS_PROTEIN_KINEMATICS_H
#define IMPKINEMATICS_PROTEIN_KINEMATICS_H

#include "kinematics_config.h"

#include <IMP/kinematics/revolute_joints.h>
#include <IMP/kinematics/KinematicForest.h>

#include <IMP/core/rigid_bodies.h>
#include <IMP/atom/Atom.h>

#include <boost/unordered_map.hpp>
#include <IMP/Vector.h>
#include <vector>
#include <iostream>

#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/undirected_dfs.hpp>

IMPKINEMATICS_BEGIN_NAMESPACE

typedef boost::adjacency_list<
    boost::vecS, boost::vecS, boost::undirectedS > Graph;

class MyDFSVisitor : public boost::default_dfs_visitor {
public:
  MyDFSVisitor(std::vector<int>& dfs_order, std::vector<int>& parents) :
    dfs_order_(dfs_order), parents_(parents), counter_(0) {}

  template < typename Vertex, typename Graph >
  void discover_vertex(Vertex v, const Graph& ) {
    dfs_order_[v] = counter_;
    counter_++;
  }

  template < typename Edge, typename Graph >
  void tree_edge(Edge e, const Graph& g) {
    std::cerr << "tree_edge " << source(e, g) << " -- " << target(e, g)
              << " dfs_order " <<  dfs_order_[source(e, g)] << " -- " <<  dfs_order_[target(e, g)] << std::endl;
    parents_[target(e,g)] = source(e, g);
  }

  std::vector<int>& dfs_order_;
  std::vector<int>& parents_;
  int counter_;
};

/**
   Defines a kinematic structure over a protein, with backbone
   and side chain dihedrals
 */
class IMPKINEMATICSEXPORT ProteinKinematics {
 public:
  /* Constructors */

  // all phi/psi rotatable
  ProteinKinematics(atom::Hierarchy mhd, bool flexible_backbone = true,
                    bool flexible_side_chains = false);

  // only torsions from dihedral_angles list are rotatable
  ProteinKinematics(atom::Hierarchy mhd,
                    const atom::Residues& flexible_residues,
                    const std::vector<atom::Atoms>& dihedral_angles,
                    atom::Atoms open_loop_bond_atoms = atom::Atoms(),
                    bool flexible_backbone = true,
                    bool flexible_side_chains = false);

 private:
  //! the actual construction is done here,
  //! see constructors for documentation
  void init( const atom::Residues& flexible_residues,
             const std::vector<atom::Atoms>& dihedral_angles,
             atom::Atoms open_loop_bond_atoms,
             bool flexible_backbone,
             bool flexible_side_chains);

  void add_edges_to_rb_graph(const std::vector<atom::Atoms>& dihedral_angles);

 public:
  /* Access methods */

  double get_phi(const atom::Residue r) const {
    return get_phi_joint(r)->get_angle();
  }

  double get_psi(const atom::Residue r) const {
    return get_psi_joint(r)->get_angle();
  }

  DihedralAngleRevoluteJoints get_joints() { return joints_; }

  DihedralAngleRevoluteJoints get_loop_joints() { return loop_joints_; }

  DihedralAngleRevoluteJoints get_ordered_joints() {
    DihedralAngleRevoluteJoints ret;
    IMP_FOREACH(Joint *j, kf_->get_ordered_joints() ){
      ret.push_back(dynamic_cast<DihedralAngleRevoluteJoint*>(j));
    }
    return ret;
  }

  KinematicForest* get_kinematic_forest() { return kf_; }
  // TODO: not sure if we have to return Pointer or just raw pointer

  core::RigidBodies get_rigid_bodies() { return rbs_; }

  // TODO: add chi

  /* Modifier methods */

  void set_phi(const atom::Residue r, double angle) {
    get_phi_joint(r)->set_angle(angle);
    kf_->update_all_external_coordinates();
  }

  void set_psi(const atom::Residue r, double angle) {
    get_psi_joint(r)->set_angle(angle);
    kf_->update_all_external_coordinates();
  }

  // TODO: add chi

 private:
  enum ProteinAngleType {
    PHI,
    PSI,
    CHI1,
    CHI2,
    CHI3,
    CHI4,
    OTHER,
    TOTAL
  };

  void build_topology_graph();

  void order_rigid_bodies(const std::vector<atom::Atoms>& dihedral_angles,
                          const std::vector<atom::Atoms>& phi_angles,
                          const std::vector<atom::Atoms>& psi_angles,
                          atom::Atoms open_loop_bond_atoms);

  void mark_rotatable_angles(const std::vector<atom::Atoms>& dihedral_angles);

  void build_rigid_bodies();

  void add_dihedral_joints(const std::vector<atom::Atoms>& dihedral_angles);

  void add_dihedral_joints(const std::vector<atom::Residue>& residues,
                           ProteinAngleType angle_type,
                           const std::vector<atom::Atoms>& dihedral_angles);

  void add_dihedral_joint(const atom::Residue r,
                          ProteinAngleType angle_type,
                          const atom::Atoms& atoms);

  void open_loop(atom::Atoms open_loop_bond_atoms);

  /* Joint access methods */
  DihedralAngleRevoluteJoint* get_phi_joint(const atom::Residue r) const {
    return (DihedralAngleRevoluteJoint*)joint_map_.get_joint(r, PHI);
  }

  DihedralAngleRevoluteJoint* get_psi_joint(const atom::Residue r) const {
    return (DihedralAngleRevoluteJoint*)joint_map_.get_joint(r, PSI);
  }

  DihedralAngleRevoluteJoint* get_other_joint(const atom::Residue r) const {
    return (DihedralAngleRevoluteJoint*)joint_map_.get_joint(r, OTHER);
  }

  //DihedralAngleRevoluteJoints get_joints(const atom::Residue r) const;

#ifndef IMP_DOXYGEN
  // A map between residue phi/psi and joints
  class AngleToJointMap {
   public:
    // Joint access
    Joint* get_joint(const atom::Residue r,
                     ProteinAngleType angle_type) const;

    // store Joint
    void add_joint(const atom::Residue r, ProteinAngleType angle_type,
                   Joint* joint);

   private:
    /* mapping to phi/psi/chi for a specific residue.
       the joints are stored using ProteinAngleType as an index */
    typedef std::vector<Joint*> ResidueJoints;
    /* mapping between residue and its joints */
    boost::unordered_map<ParticleIndex, ResidueJoints>
        residue_to_joints_;
  };
#endif  // IMP_DOXYGEN

 private:
  // protein hierarchy
  atom::Hierarchy mhd_;

  // atom particles
  ParticlesTemp atom_particles_;

  // topology graph: nodes = atoms, edges = bonds
  Graph graph_;

  // rigid bodies topology graph: node = atoms, edges = joints
  Graph rb_graph_;

  // dfs order of rigid bodies
  std::vector<int> rb_order_, parents_;

  int largest_rb_;

  // mapping between atom ParticleIndex and node number in the graph
  boost::unordered_map<ParticleIndex, int> particle_index_to_node_map_, rb_particle_index_to_node_map_;

  Vector<ParticleIndex> node_to_particle_index_map_;

  // rigid bodies
  core::RigidBodies rbs_;

  // joints
  DihedralAngleRevoluteJoints joints_;

  Pointer<kinematics::KinematicForest> kf_;

  // map between residue phi/psi/chis and joints
  AngleToJointMap joint_map_;

  boost::unordered_map<int, boost::unordered_map<int, Pointer<DihedralAngleRevoluteJoint> > > rigid_bodies_2_joint_map_;

  DihedralAngleRevoluteJoints loop_joints_;
};

IMPKINEMATICS_END_NAMESPACE

#endif /* IMPKINEMATICS_PROTEIN_KINEMATICS_H */