lsst::afw::geom::ellipses::ReducedShear Class Reference

A complex ellipticity with magnitude \(|e| = \frac{a-b}{a+b} \). More...

#include <ReducedShear.h>

Inheritance diagram for lsst::afw::geom::ellipses::ReducedShear:

Public Types
enum	ParameterEnum { E1 = 0 , E2 = 1 }
using	Jacobian = Eigen::Matrix2d

Public Member Functions
	ReducedShear (std::complex< double > const &complex)
	ReducedShear (double e1=0.0, double e2=0.0)
	ReducedShear (ReducedShear const &other)
	ReducedShear (ReducedShear &&other)
	~ReducedShear ()=default
	ReducedShear (Distortion const &other)
	ReducedShear (ConformalShear const &other)
ReducedShear &	operator= (ReducedShear const &other)
ReducedShear &	operator= (ReducedShear &&other)
ReducedShear &	operator= (Distortion const &other)
ReducedShear &	operator= (ConformalShear const &other)
Jacobian	dAssign (ReducedShear const &other)
Jacobian	dAssign (Distortion const &other)
Jacobian	dAssign (ConformalShear const &other)
double	getAxisRatio () const
void	normalize ()
std::complex< double > &	getComplex ()
std::complex< double > const &	getComplex () const
void	setComplex (std::complex< double > const &v)
double	getE1 () const
void	setE1 (double e1)
double	getE2 () const
void	setE2 (double e2)
double	getE () const
void	setE (double e)
double	getTheta () const

Static Public Member Functions
static std::string	getName ()

Protected Attributes
std::complex< double >	_complex

Detailed Description

A complex ellipticity with magnitude \(|e| = \frac{a-b}{a+b} \).

For a more complete definition, see Bernstein and Jarvis (2002); this the same as their reduced shear \(g\) (eq. 2.8).

Definition at line 45 of file ReducedShear.h.

Member Typedef Documentation

Jacobian

using lsst::afw::geom::ellipses::detail::EllipticityBase::Jacobian = Eigen::Matrix2d

inherited

Definition at line 47 of file EllipticityBase.h.

Member Enumeration Documentation

ParameterEnum

enum lsst::afw::geom::ellipses::detail::EllipticityBase::ParameterEnum

inherited

Enumerator
E1
E2

Definition at line 49 of file EllipticityBase.h.

{ E1 = 0, E2 = 1 };

Constructor & Destructor Documentation

ReducedShear() [1/6]

lsst::afw::geom::ellipses::ReducedShear::ReducedShear ( std::complex< double > const & complex )

inlineexplicit

Definition at line 47 of file ReducedShear.h.

: detail::EllipticityBase(complex) {}

ReducedShear() [2/6]

lsst::afw::geom::ellipses::ReducedShear::ReducedShear ( double e1 = 0.0, double e2 = 0.0 )

inlineexplicit

Definition at line 49 of file ReducedShear.h.

: detail::EllipticityBase(e1, e2) {}

ReducedShear() [3/6]

lsst::afw::geom::ellipses::ReducedShear::ReducedShear ( ReducedShear const & other )

inline

Definition at line 51 of file ReducedShear.h.

: detail::EllipticityBase(other.getComplex()) {}

ReducedShear() [4/6]

lsst::afw::geom::ellipses::ReducedShear::ReducedShear ( ReducedShear && other )

inline

Definition at line 53 of file ReducedShear.h.

: ReducedShear(other) {}

~ReducedShear()

lsst::afw::geom::ellipses::ReducedShear::~ReducedShear ( )

default

ReducedShear() [5/6]

lsst::afw::geom::ellipses::ReducedShear::ReducedShear ( Distortion const & other )

inlineexplicit

Definition at line 56 of file ReducedShear.h.

{ this->operator=(other); }

ReducedShear() [6/6]

lsst::afw::geom::ellipses::ReducedShear::ReducedShear ( ConformalShear const & other )

inlineexplicit

Definition at line 58 of file ReducedShear.h.

{ this->operator=(other); }

Member Function Documentation

dAssign() [1/3]

detail::EllipticityBase::Jacobian lsst::afw::geom::ellipses::ReducedShear::dAssign

(

ConformalShear const &

other

)

Definition at line 79 of file ReducedShear.cc.

                                                                               {
    Jacobian result = Jacobian::Zero();
    double eta = other.getE();
    double alpha, beta;
    if (eta < 1E-8) {
        alpha = 0.5 - eta * eta / 24.0;
        beta = -1.0 / 12;
    } else {
        double g = std::tanh(0.5 * eta);
        alpha = g / eta;
        beta = (0.5 * (1.0 - g * g) - alpha) / (eta * eta);
    }
    _complex = other.getComplex() * alpha;
    result(0, 0) = alpha + other.getE1() * other.getE1() * beta;
    result(1, 1) = alpha + other.getE2() * other.getE2() * beta;
    result(1, 0) = result(0, 1) = other.getE1() * other.getE2() * beta;
    return result;
}

dAssign() [2/3]

detail::EllipticityBase::Jacobian lsst::afw::geom::ellipses::ReducedShear::dAssign

(

Distortion const &

other

)

Definition at line 60 of file ReducedShear.cc.

                                                                           {
    Jacobian result = Jacobian::Zero();
    double delta = other.getE();
    double s = std::sqrt(1.0 - delta * delta);
    double alpha, beta;
    if (delta < 1E-8) {
        alpha = 0.5 + 0.125 * delta * delta;
        beta = 0.25;
    } else {
        alpha = (1.0 - s) / (delta * delta);
        beta = (2.0 * alpha - 1.0) / (delta * delta * s);
    }
    _complex = other.getComplex() * alpha;
    result(0, 0) = alpha + other.getE1() * other.getE1() * beta;
    result(1, 1) = alpha + other.getE2() * other.getE2() * beta;
    result(1, 0) = result(0, 1) = other.getE1() * other.getE2() * beta;
    return result;
}

dAssign() [3/3]

Jacobian lsst::afw::geom::ellipses::ReducedShear::dAssign ( ReducedShear const & other )

inline

Definition at line 71 of file ReducedShear.h.

                                                {
        _complex = other._complex;
        return Jacobian::Identity();
    }

getAxisRatio()

double lsst::afw::geom::ellipses::ReducedShear::getAxisRatio

(

)

const

Definition at line 33 of file ReducedShear.cc.

                                        {
    double e = getE();
    return (1.0 - e) / (1.0 + e);
}

getComplex() [1/2]

std::complex< double > & lsst::afw::geom::ellipses::detail::EllipticityBase::getComplex ( )

inlineinherited

Definition at line 51 of file EllipticityBase.h.

{ return _complex; }

getComplex() [2/2]

std::complex< double > const & lsst::afw::geom::ellipses::detail::EllipticityBase::getComplex ( ) const

inlineinherited

Definition at line 53 of file EllipticityBase.h.

{ return _complex; }

getE()

double lsst::afw::geom::ellipses::detail::EllipticityBase::getE ( ) const

inlineinherited

Definition at line 75 of file EllipticityBase.h.

{ return std::sqrt(std::norm(_complex)); }

getE1()

double lsst::afw::geom::ellipses::detail::EllipticityBase::getE1 ( ) const

inlineinherited

Definition at line 57 of file EllipticityBase.h.

{ return _complex.real(); }

getE2()

double lsst::afw::geom::ellipses::detail::EllipticityBase::getE2 ( ) const

inlineinherited

Definition at line 66 of file EllipticityBase.h.

{ return _complex.imag(); }

getName()

static std::string lsst::afw::geom::ellipses::ReducedShear::getName ( )

inlinestatic

Definition at line 84 of file ReducedShear.h.

{ return "ReducedShear"; }

getTheta()

double lsst::afw::geom::ellipses::detail::EllipticityBase::getTheta ( ) const

inlineinherited

Definition at line 78 of file EllipticityBase.h.

{ return 0.5 * std::arg(_complex); }

normalize()

void lsst::afw::geom::ellipses::ReducedShear::normalize ( )

inline

Definition at line 82 of file ReducedShear.h.

{}

operator=() [1/4]

ReducedShear & lsst::afw::geom::ellipses::ReducedShear::operator=

(

ConformalShear const &

other

)

Definition at line 49 of file ReducedShear.cc.

                                                                 {
    double eta = other.getE();
    if (eta < 1E-8) {
        _complex = other.getComplex() * (0.5 - eta * eta / 12.0);
    } else {
        double g = std::tanh(0.5 * eta);
        _complex = other.getComplex() * g / eta;
    }
    return *this;
}

operator=() [2/4]

ReducedShear & lsst::afw::geom::ellipses::ReducedShear::operator=

(

Distortion const &

other

)

Definition at line 38 of file ReducedShear.cc.

                                                             {
    double delta = other.getE();
    if (delta < 1E-8) {
        _complex = other.getComplex() * (0.5 + 0.125 * delta * delta);
    } else {
        double g = (1.0 - std::sqrt(1.0 - delta * delta)) / delta;
        _complex = other.getComplex() * g / delta;
    }
    return *this;
}

operator=() [3/4]

ReducedShear & lsst::afw::geom::ellipses::ReducedShear::operator= ( ReducedShear && other )

inline

Definition at line 65 of file ReducedShear.h.

{ return *this = other; }

operator=() [4/4]

ReducedShear & lsst::afw::geom::ellipses::ReducedShear::operator= ( ReducedShear const & other )

inline

Definition at line 60 of file ReducedShear.h.

                                                       {
        _complex = other._complex;
        return *this;
    }

setComplex()

void lsst::afw::geom::ellipses::detail::EllipticityBase::setComplex ( std::complex< double > const & v )

inlineinherited

Definition at line 55 of file EllipticityBase.h.

{ _complex = v; }

setE()

void lsst::afw::geom::ellipses::detail::EllipticityBase::setE ( double e )

inlineinherited

Definition at line 76 of file EllipticityBase.h.

{ _complex *= e / getE(); }

setE1()

void lsst::afw::geom::ellipses::detail::EllipticityBase::setE1 ( double e1 )

inlineinherited

Definition at line 58 of file EllipticityBase.h.

                          {
#if __cplusplus < 201103L
        _complex = std::complex<double>(e1, _complex.imag());
#else
        _complex.real(e1);
#endif
    }

setE2()

void lsst::afw::geom::ellipses::detail::EllipticityBase::setE2 ( double e2 )

inlineinherited

Definition at line 67 of file EllipticityBase.h.

                          {
#if __cplusplus < 201103L
        _complex = std::complex<double>(_complex.real(), e2);
#else
        _complex.imag(e2);
#endif
    }

Member Data Documentation

_complex

std::complex<double> lsst::afw::geom::ellipses::detail::EllipticityBase::_complex

protectedinherited

Definition at line 91 of file EllipticityBase.h.

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The documentation for this class was generated from the following files:

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/afw/g5a732f18d5+53520f316c/include/lsst/afw/geom/ellipses/ReducedShear.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/afw/g5a732f18d5+53520f316c/src/geom/ellipses/ReducedShear.cc