GeographicLib: AuxAngle.cpp Source File

GeographicLib 2.6

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AuxAngle.cpp
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1/**
2 * \file AuxAngle.cpp
3 * \brief Implementation for the GeographicLib::AuxAngle class.
4 *
5 * This file is an implementation of the methods described in
6 * - C. F. F. Karney,
7 * <a href="https://doi.org/10.1080/00396265.2023.2217604">
8 * On auxiliary latitudes,</a>
9 * Survey Review 56(395), 165--180 (2024);
10 * preprint
11 * <a href="https://arxiv.org/abs/2212.05818">arXiv:2212.05818</a>.
12 * .
13 * Copyright (c) Charles Karney (2022-2023) <karney@alum.mit.edu> and licensed
14 * under the MIT/X11 License. For more information, see
15 * https://geographiclib.sourceforge.io/
16 **********************************************************************/
17
18#include <GeographicLib/AuxAngle.hpp>
19
20namespace GeographicLib {
21
22 using namespace std;
23
24 AuxAngle AuxAngle::NaN() {
25 return AuxAngle(Math::NaN(), Math::NaN());
26 }
27
28 AuxAngle AuxAngle::normalized() const {
29 if ( isnan( tan() ) ||
30 (fabs(_y) > numeric_limits<real>::max()/2 &&
31 fabs(_x) > numeric_limits<real>::max()/2) )
32 // deal with
33 // (0,0), (inf,inf), (nan,nan), (nan,x), (y,nan), (toobig,toobig)
34 return NaN();
35 real r = hypot(_y, _x),
36 y = _y/r, x = _x/r;
37 // deal with r = inf, then one of y,x becomes 1
38 if (isnan(y)) y = copysign(real(1), _y);
39 if (isnan(x)) x = copysign(real(1), _x);
40 return AuxAngle(y, x);
41 }
42
43 AuxAngle AuxAngle::copyquadrant(const AuxAngle& p) const {
44 return AuxAngle(copysign(y(), p.y()), copysign(x(), p.x()));
45 }
46
47 AuxAngle& AuxAngle::operator+=(const AuxAngle& p) {
48 // Do nothing if p.tan() == 0 to preserve signs of y() and x()
49 if (p.tan() != 0) {
50 real x = _x * p._x - _y * p._y;
51 _y = _y * p._x + _x * p._y;
52 _x = x;
53 }
54 return *this;
55 }
56
57} // namespace GeographicLib
AuxAngle.hpp
Header for the GeographicLib::AuxAngle class.
real
GeographicLib::Math::real real
Definition Geod3Solve.cpp:25
GeographicLib::AuxAngle::y
Math::real y() const
Definition AuxAngle.hpp:74
GeographicLib::AuxAngle::x
Math::real x() const
Definition AuxAngle.hpp:79
GeographicLib::AuxAngle::normalized
AuxAngle normalized() const
Definition AuxAngle.cpp:28
GeographicLib::AuxAngle::operator+=
AuxAngle & operator+=(const AuxAngle &p)
Definition AuxAngle.cpp:47
GeographicLib::AuxAngle::NaN
static AuxAngle NaN()
Definition AuxAngle.cpp:24
GeographicLib::AuxAngle::tan
Math::real tan() const
Definition AuxAngle.hpp:117
GeographicLib::AuxAngle::copyquadrant
AuxAngle copyquadrant(const AuxAngle &p) const
Definition AuxAngle.cpp:43
GeographicLib::AuxAngle::AuxAngle
AuxAngle(real y=0, real x=1)
Definition AuxAngle.hpp:69
GeographicLib::Math::NaN
static T NaN()
Definition Math.cpp:301
GeographicLib
Namespace for GeographicLib.
Definition Accumulator.cpp:12