Ellipsoid.cpp
Go to the documentation of this file.
/**
* \file Ellipsoid.cpp
* \brief Implementation for GeographicLib::Ellipsoid class
*
* Copyright (c) Charles Karney (2012-2023) <karney@alum.mit.edu> and licensed
* under the MIT/X11 License. For more information, see
* https://geographiclib.sourceforge.io/
**********************************************************************/
#include <GeographicLib/Ellipsoid.hpp>
#if defined(_MSC_VER)
// Squelch warnings about enum-float expressions
# pragma warning (disable: 5055)
#endif
namespace GeographicLib {
using namespace std;
/// \cond SKIP
Ellipsoid::Ellipsoid(real a, real f)
: stol_(real(0.01) * sqrt(numeric_limits<real>::epsilon()))
, _a(a)
, _f(f)
, _b(_a * (1 - _f))
, _e2(_f * (2 - _f))
, _e12(_e2 / (1 - _e2))
, _n(_f / (2 - _f))
, _aux(_a, _f)
, _rm(_aux.RectifyingRadius(true))
, _c2(_aux.AuthalicRadiusSquared(true))
{}
/// \endcond
const Ellipsoid& Ellipsoid::WGS84() {
static const Ellipsoid wgs84(Constants::WGS84_a(), Constants::WGS84_f());
return wgs84;
}
Math::real Ellipsoid::QuarterMeridian() const
{ return Math::pi()/2 * _rm; }
Math::real Ellipsoid::Area() const
{ return 4 * Math::pi() * _c2; }
Math::real Ellipsoid::ParametricLatitude(real phi) const {
return _aux.Convert(AuxLatitude::PHI, AuxLatitude::BETA,
Math::LatFix(phi), true);
}
Math::real Ellipsoid::InverseParametricLatitude(real beta) const {
return _aux.Convert(AuxLatitude::BETA, AuxLatitude::PHI,
Math::LatFix(beta), true);
}
Math::real Ellipsoid::GeocentricLatitude(real phi) const {
return _aux.Convert(AuxLatitude::PHI, AuxLatitude::THETA,
Math::LatFix(phi), true);
}
Math::real Ellipsoid::InverseGeocentricLatitude(real theta) const {
return _aux.Convert(AuxLatitude::THETA, AuxLatitude::PHI,
Math::LatFix(theta), true);
}
Math::real Ellipsoid::RectifyingLatitude(real phi) const {
return _aux.Convert(AuxLatitude::PHI, AuxLatitude::MU,
Math::LatFix(phi), true);
}
Math::real Ellipsoid::InverseRectifyingLatitude(real mu) const {
return _aux.Convert(AuxLatitude::MU, AuxLatitude::PHI,
Math::LatFix(mu), true);
}
Math::real Ellipsoid::AuthalicLatitude(real phi) const {
return _aux.Convert(AuxLatitude::PHI, AuxLatitude::XI,
Math::LatFix(phi), true);
}
Math::real Ellipsoid::InverseAuthalicLatitude(real xi) const {
return _aux.Convert(AuxLatitude::XI, AuxLatitude::PHI,
Math::LatFix(xi), true);
}
Math::real Ellipsoid::ConformalLatitude(real phi) const {
return _aux.Convert(AuxLatitude::PHI, AuxLatitude::CHI,
Math::LatFix(phi), true);
}
Math::real Ellipsoid::InverseConformalLatitude(real chi) const {
return _aux.Convert(AuxLatitude::CHI, AuxLatitude::PHI,
Math::LatFix(chi), true);
}
Math::real Ellipsoid::IsometricLatitude(real phi) const {
return _aux.Convert(AuxLatitude::PHI, AuxLatitude::CHI,
AuxAngle::degrees(Math::LatFix(phi)), true).lamd();
}
Math::real Ellipsoid::InverseIsometricLatitude(real psi) const {
return _aux.Convert(AuxLatitude::CHI, AuxLatitude::PHI,
AuxAngle::lamd(psi), true).degrees();
}
Math::real Ellipsoid::CircleRadius(real phi) const {
// a * cos(beta)
AuxAngle beta(_aux.Convert(AuxLatitude::PHI, AuxLatitude::BETA,
AuxAngle::degrees(Math::LatFix(phi)),
true).normalized());
return _a * beta.x();
}
Math::real Ellipsoid::CircleHeight(real phi) const {
// b * sin(beta)
AuxAngle beta(_aux.Convert(AuxLatitude::PHI, AuxLatitude::BETA,
AuxAngle::degrees(Math::LatFix(phi)),
true).normalized());
return _b * beta.y();
}
Math::real Ellipsoid::MeridianDistance(real phi) const {
return _rm * _aux.Convert(AuxLatitude::PHI, AuxLatitude::MU,
AuxAngle::degrees(Math::LatFix(phi)),
true).radians();
}
Math::real Ellipsoid::MeridionalCurvatureRadius(real phi) const {
real v = 1 - _e2 * Math::sq(Math::sind(Math::LatFix(phi)));
return _a * (1 - _e2) / (v * sqrt(v));
}
Math::real Ellipsoid::TransverseCurvatureRadius(real phi) const {
real v = 1 - _e2 * Math::sq(Math::sind(Math::LatFix(phi)));
return _a / sqrt(v);
}
Math::real Ellipsoid::NormalCurvatureRadius(real phi, real azi) const {
real calp, salp,
v = 1 - _e2 * Math::sq(Math::sind(Math::LatFix(phi)));
Math::sincosd(azi, salp, calp);
return _a / (sqrt(v) * (Math::sq(calp) * v / (1 - _e2) + Math::sq(salp)));
}
} // namespace GeographicLib
Ellipsoid.hpp
Header for GeographicLib::Ellipsoid class.
real
GeographicLib::Math::real real
Definition: GeodSolve.cpp:29
GeographicLib::AuxAngle
An accurate representation of angles.
Definition: AuxAngle.hpp:47
GeographicLib::AuxAngle::y
Math::real y() const
Definition: AuxAngle.hpp:70
GeographicLib::AuxAngle::x
Math::real x() const
Definition: AuxAngle.hpp:75
GeographicLib::Ellipsoid
Properties of an ellipsoid.
Definition: Ellipsoid.hpp:31
GeographicLib::Ellipsoid::Ellipsoid
Ellipsoid(real a, real f)
GeographicLib::Math::real
double real
Definition: Math.hpp:100
GeographicLib
Namespace for GeographicLib.
Definition: Accumulator.cpp:12
std
Definition: NearestNeighbor.hpp:812