LSSTApplications  20.0.0
LSSTDataManagementBasePackage
ConformalShear.cc
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1 // -*- lsst-c++ -*-
2 
3 /*
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24 #include <cmath>
25 
29 
30 namespace lsst {
31 namespace afw {
32 namespace geom {
33 namespace ellipses {
34 
36  double e = getE();
37  return std::exp(-e);
38 }
39 
41  double delta = other.getE();
42  if (delta < 1E-8) {
43  _complex = other.getComplex() * (1.0 + delta * delta / 3.0);
44  } else {
45  double eta = std::atanh(delta);
46  _complex = other.getComplex() * eta / delta;
47  }
48  return *this;
49 }
50 
52  double g = other.getE();
53  if (g < 1E-8) {
54  _complex = other.getComplex() * 2.0 * (1.0 + g * g / 3.0);
55  } else {
56  double eta = 2.0 * std::atanh(g);
57  _complex = other.getComplex() * eta / g;
58  }
59  return *this;
60 }
61 
63  Jacobian result = Jacobian::Zero();
64  double delta = other.getE();
65  double alpha, beta;
66  if (delta < 1E-8) {
67  alpha = 1.0 + delta * delta / 3.0;
68  beta = 2.0 / 3.0;
69  } else {
70  double eta = std::atanh(delta);
71  alpha = eta / delta;
72  beta = (1.0 / (1.0 - delta * delta) - alpha) / (delta * delta);
73  }
74  _complex = other.getComplex() * alpha;
75  result(0, 0) = alpha + other.getE1() * other.getE1() * beta;
76  result(1, 1) = alpha + other.getE2() * other.getE2() * beta;
77  result(1, 0) = result(0, 1) = other.getE1() * other.getE2() * beta;
78  return result;
79 }
80 
82  Jacobian result = Jacobian::Zero();
83  double g = other.getE();
84  double alpha, beta;
85  if (g < 1E-8) {
86  alpha = 2.0 * (1.0 + g * g / 3.0);
87  beta = 4.0 / 3.0;
88  } else {
89  double eta = 2.0 * std::atanh(g);
90  alpha = eta / g;
91  beta = 1.0 * (2.0 / (1.0 - g * g) - alpha) / (g * g);
92  }
93  _complex = other.getComplex() * alpha;
94  result(0, 0) = alpha + other.getE1() * other.getE1() * beta;
95  result(1, 1) = alpha + other.getE2() * other.getE2() * beta;
96  result(1, 0) = result(0, 1) = other.getE1() * other.getE2() * beta;
97  return result;
98 }
99 } // namespace ellipses
100 } // namespace geom
101 } // namespace afw
102 } // namespace lsst
ellipses
Distortion.h
lsst::afw
Definition: imageAlgorithm.dox:1
lsst::afw::geom::ellipses::ConformalShear
A logarithmic complex ellipticity with magnitude .
Definition: ConformalShear.h:45
ConformalShear.h
lsst::afw::geom::ellipses::detail::EllipticityBase::Jacobian
Eigen::Matrix2d Jacobian
Definition: EllipticityBase.h:47
other
ItemVariant const * other
Definition: Schema.cc:56
lsst::afw::geom::ellipses::detail::EllipticityBase::_complex
std::complex< double > _complex
Definition: EllipticityBase.h:91
lsst::afw::geom::ellipses::ReducedShear
A complex ellipticity with magnitude .
Definition: ReducedShear.h:45
std::atanh
T atanh(T... args)
result
py::object result
Definition: _schema.cc:429
lsst::afw::geom::ellipses::detail::EllipticityBase::getE
double getE() const
Definition: EllipticityBase.h:75
lsst
A base class for image defects.
Definition: imageAlgorithm.dox:1
lsst::geom
Definition: geomOperators.dox:4
std::exp
T exp(T... args)
ReducedShear.h
lsst::afw::geom::ellipses::ConformalShear::getAxisRatio
double getAxisRatio() const
Definition: ConformalShear.cc:35
lsst::afw::geom::ellipses::ConformalShear::operator=
ConformalShear & operator=(ConformalShear const &other)
Definition: ConformalShear.h:60
lsst::afw::geom::ellipses::ConformalShear::dAssign
Jacobian dAssign(ConformalShear const &other)
Definition: ConformalShear.h:71
lsst::afw::geom::ellipses::Distortion
A complex ellipticity with magnitude .
Definition: Distortion.h:44