Similarity2.h

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/* ----------------------------------------------------------------------------
 
 * GTSAM Copyright 2010, Georgia Tech Research Corporation,
 * Atlanta, Georgia 30332-0415
 * All Rights Reserved
 * Authors: Frank Dellaert, et al. (see THANKS for the full author list)
 
 * See LICENSE for the license information
 
 * -------------------------------------------------------------------------- */

 
#pragma once
 
#include <gtsam/base/MatrixLieGroup.h>
#include <gtsam/dllexport.h>
#include <gtsam/geometry/Point2.h>
#include <gtsam/geometry/Pose2.h>
#include <gtsam/geometry/Rot2.h>
 
namespace gtsam {
 
// Forward declarations
class Pose2;

class GTSAM_EXPORT Similarity2 : public MatrixLieGroup<Similarity2, 4, 3> {
  typedef Rot2 Rotation;
  typedef Point2 Translation;
 
private:
  Rot2 R_;
  Point2 t_;
  double s_;
 
public:

  Similarity2();

  Similarity2(double s);

  Similarity2(const Rot2& R, const Point2& t, double s);

  Similarity2(const Matrix2& R, const Vector2& t, double s);

  Similarity2(const Matrix3& T);


  bool equals(const Similarity2& sim, double tol) const;

  bool operator==(const Similarity2& other) const;

  void print(const std::string& s = "") const;
 
  GTSAM_EXPORT friend std::ostream& operator<<(std::ostream& os,
                                               const Similarity2& p);


  static Similarity2 Identity();

  Similarity2 operator*(const Similarity2& S) const;

  Similarity2 inverse() const;


  Point2 transformFrom(const Point2& p) const;

  Pose2 transformFrom(const Pose2& T) const;
 
  /* syntactic sugar for transformFrom */
  Point2 operator*(const Point2& p) const;

  static Similarity2 Align(const Point2Pairs& abPointPairs);

  static Similarity2 Align(const Pose2Pairs& abPosePairs);

 
  using LieAlgebra = Matrix3;

  static Matrix2 GetV(double theta, double lambda);

  static Vector4 Logmap(const Similarity2& S);

  static Similarity2 Expmap(const Vector4& v);

  struct ChartAtOrigin {
    static Similarity2 Retract(const Vector4& v) {
      return Similarity2::Expmap(v);
    }
    static Vector4 Local(const Similarity2& other) {
      return Similarity2::Logmap(other);
    }
  };

  Matrix4 AdjointMap() const;
 
  using LieGroup<Similarity2, 4>::inverse;

  static Matrix3 Hat(const Vector4& xi);

  static Vector4 Vee(const Matrix3& X);


  Matrix3 matrix() const;

  Rot2 rotation() const { return R_; }

  Point2 translation() const { return t_; }

  double scale() const { return s_; }
 
 private:
 
  #if GTSAM_ENABLE_BOOST_SERIALIZATION
    friend class boost::serialization::access;
    template<class Archive>
    void serialize(Archive & ar, const unsigned int /*version*/) {
      ar & BOOST_SERIALIZATION_NVP(R_);
      ar & BOOST_SERIALIZATION_NVP(t_);
      ar & BOOST_SERIALIZATION_NVP(s_);
    }
  #endif

};
 
template <>
struct traits<Similarity2> : public internal::MatrixLieGroup<Similarity2, 3> {};
 
template <>
struct traits<const Similarity2> : public internal::MatrixLieGroup<Similarity2, 3> {};
 
}  // namespace gtsam