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/Lie.h>
#include <gtsam/base/Manifold.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 LieGroup<Similarity2, 4> {
  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;

  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);


  static Vector4 Logmap(const Similarity2& S,  //
                        OptionalJacobian<4, 4> Hm = {});

  static Similarity2 Expmap(const Vector4& v,  //
                            OptionalJacobian<4, 4> Hm = {});

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

  Matrix4 AdjointMap() const;

  using LieGroup<Similarity2, 4>::inverse;


  Matrix3 matrix() const;

  Rot2 rotation() const { return R_; }

  Point2 translation() const { return t_; }

  double scale() const { return s_; }

  inline static size_t Dim() { return 4; }

  inline size_t dim() const { return 4; }

};

template <>
struct traits<Similarity2> : public internal::LieGroup<Similarity2> {};

template <>
struct traits<const Similarity2> : public internal::LieGroup<Similarity2> {};

}  // namespace gtsam