gtsam/base/LieScalar.h

76 lines
1.9 KiB
C++

/* ----------------------------------------------------------------------------
* 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
* -------------------------------------------------------------------------- */
/**
* @file LieScalar.h
* @brief A wrapper around scalar providing Lie compatibility
* @author Kai Ni
*/
#pragma once
#include <gtsam/base/Testable.h>
#include <gtsam/base/Lie.h>
namespace gtsam {
/**
* LieScalar is a wrapper around double to allow it to be a Lie type
*/
struct LieScalar : public Lie<LieScalar>, Testable<LieScalar> {
/** default constructor - should be unnecessary */
LieScalar() {}
/** wrap a double */
LieScalar(double d) : d_(d) {}
/** print @param s optional string naming the object */
inline void print(const std::string& name="") const {
std::cout << name << ": " << d_ << std::endl;
}
/** equality up to tolerance */
inline bool equals(const LieScalar& expected, double tol=1e-5) const {
return fabs(expected.d_ - d_) <= tol;
}
/**
* Returns dimensionality of the tangent space
*/
inline size_t dim() const { return 1; }
/**
* Returns Exponential map update of T
* Default implementation calls global binary function
*/
inline LieScalar expmap(const Vector& v) const { return LieScalar(d_ + v(0)); }
/** expmap around identity */
static inline LieScalar Expmap(const Vector& v) { return LieScalar(v(0)); }
/**
* Returns Log map
* Default Implementation calls global binary function
*/
inline Vector logmap(const LieScalar& lp) const {
return Vector_(1, lp.d_ - d_);
}
/** Logmap around identity - just returns with default cast back */
static inline Vector Logmap(const LieScalar& p) { return Vector_(1, p.d_); }
private:
double d_;
};
} // \namespace gtsam