lsst::afw::geom::ellipses::BaseCore::Transformer Class Reference

A temporary-only expression object for ellipse core transformations. More...

#include <Transformer.h>

Public Types
typedef Eigen::Matrix3d	DerivativeMatrix
	Matrix type for derivative with respect to input ellipse parameters. More...
typedef Eigen::Matrix< double, 3, 4 >	TransformDerivativeMatrix
	Matrix type for derivative with respect to transform parameters. More...

Public Member Functions
	Transformer (BaseCore &input_, lsst::geom::LinearTransform const &transform_)
	Standard constructor. More...
std::shared_ptr< BaseCore >	copy () const
	Return a new transformed ellipse core. More...
void	inPlace ()
	Transform the ellipse core in-place. More...
void	apply (BaseCore &result) const
DerivativeMatrix	d () const
	Return the derivative of transformed core with respect to input core. More...
TransformDerivativeMatrix	dTransform () const
	Return the derivative of transformed core with respect to transform parameters. More...

Public Attributes
BaseCore &	input
	input core to be transformed More...
lsst::geom::LinearTransform const &	transform
	transform object More...

Detailed Description

A temporary-only expression object for ellipse core transformations.

Transformer simply provides a clean syntax for transform-related operations, including in-place and new-object transformations, derivatives of the transformations, and implicit conversion to a shared_ptr to a new transformed core.

Definition at line 49 of file Transformer.h.

Member Typedef Documentation

DerivativeMatrix

typedef Eigen::Matrix3d lsst::afw::geom::ellipses::BaseCore::Transformer::DerivativeMatrix

Matrix type for derivative with respect to input ellipse parameters.

Definition at line 52 of file Transformer.h.

TransformDerivativeMatrix

typedef Eigen::Matrix<double, 3, 4> lsst::afw::geom::ellipses::BaseCore::Transformer::TransformDerivativeMatrix

Matrix type for derivative with respect to transform parameters.

Definition at line 55 of file Transformer.h.

Constructor & Destructor Documentation

Transformer()

lsst::afw::geom::ellipses::BaseCore::Transformer::Transformer ( BaseCore &  input_, lsst::geom::LinearTransform const &  transform_  )

inline

Standard constructor.

Definition at line 58 of file Transformer.h.

            : input(input_), transform(transform_) {}

Member Function Documentation

apply()

void lsst::afw::geom::ellipses::BaseCore::Transformer::apply

(

BaseCore &

result

)

const

Definition at line 41 of file Transformer.cc.

                                                      {
    Eigen::Matrix2d m;
    input._assignToQuadrupole(m(0, 0), m(1, 1), m(0, 1));
    m(1, 0) = m(0, 1);
    m = transform.getMatrix() * m * transform.getMatrix().transpose();
    result._assignFromQuadrupole(m(0, 0), m(1, 1), m(0, 1));
}

copy()

std::shared_ptr< BaseCore > lsst::afw::geom::ellipses::BaseCore::Transformer::copy

(

)

const

Return a new transformed ellipse core.

Definition at line 33 of file Transformer.cc.

                                                        {
    std::shared_ptr<BaseCore> r(input.clone());
    apply(*r);
    return r;
}

d()

BaseCore::Transformer::DerivativeMatrix lsst::afw::geom::ellipses::BaseCore::Transformer::d

(

)

const

Return the derivative of transformed core with respect to input core.

Definition at line 49 of file Transformer.cc.

                                                                 {
    std::shared_ptr<BaseCore> output(input.clone());
    Eigen::Matrix2d m;
    Jacobian rhs = input._dAssignToQuadrupole(m(0, 0), m(1, 1), m(0, 1));
    m(1, 0) = m(0, 1);
    m = transform.getMatrix() * m * transform.getMatrix().transpose();
    Jacobian lhs = output->_dAssignFromQuadrupole(m(0, 0), m(1, 1), m(0, 1));
    Jacobian mid = Jacobian::Zero();
    mid(0, 0) = transform[lsst::geom::LinearTransform::XX] * transform[lsst::geom::LinearTransform::XX];
    mid(0, 1) = transform[lsst::geom::LinearTransform::XY] * transform[lsst::geom::LinearTransform::XY];
    mid(0, 2) = 2 * transform[lsst::geom::LinearTransform::XY] * transform[lsst::geom::LinearTransform::XX];
    mid(1, 0) = transform[lsst::geom::LinearTransform::YX] * transform[lsst::geom::LinearTransform::YX];
    mid(1, 1) = transform[lsst::geom::LinearTransform::YY] * transform[lsst::geom::LinearTransform::YY];
    mid(1, 2) = 2 * transform[lsst::geom::LinearTransform::YY] * transform[lsst::geom::LinearTransform::YX];
    mid(2, 0) = transform[lsst::geom::LinearTransform::YX] * transform[lsst::geom::LinearTransform::XX];
    mid(2, 1) = transform[lsst::geom::LinearTransform::YY] * transform[lsst::geom::LinearTransform::XY];
    mid(2, 2) = transform[lsst::geom::LinearTransform::XX] * transform[lsst::geom::LinearTransform::YY] +
                transform[lsst::geom::LinearTransform::XY] * transform[lsst::geom::LinearTransform::YX];
    return lhs * mid * rhs;
}

dTransform()

BaseCore::Transformer::TransformDerivativeMatrix lsst::afw::geom::ellipses::BaseCore::Transformer::dTransform

(

)

const

Return the derivative of transformed core with respect to transform parameters.

Definition at line 70 of file Transformer.cc.

                                                                                   {
    std::shared_ptr<BaseCore> output(input.clone());
    Eigen::Matrix2d m;
    input._assignToQuadrupole(m(0, 0), m(1, 1), m(0, 1));
    Eigen::Matrix<double, 3, 4> mid = Eigen::Matrix<double, 3, 4>::Zero();
    m(1, 0) = m(0, 1);
    mid(0, lsst::geom::LinearTransform::XX) = 2.0 * (transform[lsst::geom::LinearTransform::XX] * m(0, 0) +
                                                     transform[lsst::geom::LinearTransform::XY] * m(0, 1));
    mid(0, lsst::geom::LinearTransform::XY) = 2.0 * (transform[lsst::geom::LinearTransform::XX] * m(0, 1) +
                                                     transform[lsst::geom::LinearTransform::XY] * m(1, 1));
    mid(1, lsst::geom::LinearTransform::YX) = 2.0 * (transform[lsst::geom::LinearTransform::YX] * m(0, 0) +
                                                     transform[lsst::geom::LinearTransform::YY] * m(0, 1));
    mid(1, lsst::geom::LinearTransform::YY) = 2.0 * (transform[lsst::geom::LinearTransform::YX] * m(0, 1) +
                                                     transform[lsst::geom::LinearTransform::YY] * m(1, 1));
    mid(2, lsst::geom::LinearTransform::XX) = transform[lsst::geom::LinearTransform::YX] * m(0, 0) +
                                              transform[lsst::geom::LinearTransform::YY] * m(0, 1);
    mid(2, lsst::geom::LinearTransform::XY) = transform[lsst::geom::LinearTransform::YX] * m(0, 1) +
                                              transform[lsst::geom::LinearTransform::YY] * m(1, 1);
    mid(2, lsst::geom::LinearTransform::YX) = transform[lsst::geom::LinearTransform::XX] * m(0, 0) +
                                              transform[lsst::geom::LinearTransform::XY] * m(0, 1);
    mid(2, lsst::geom::LinearTransform::YY) = transform[lsst::geom::LinearTransform::XX] * m(0, 1) +
                                              transform[lsst::geom::LinearTransform::XY] * m(1, 1);
    m = transform.getMatrix() * m * transform.getMatrix().transpose();
    Jacobian lhs = output->_dAssignFromQuadrupole(m(0, 0), m(1, 1), m(0, 1));
    return lhs * mid;
}

inPlace()

void lsst::afw::geom::ellipses::BaseCore::Transformer::inPlace

(

)

Transform the ellipse core in-place.

Definition at line 39 of file Transformer.cc.

{ apply(input); }

Member Data Documentation

input

BaseCore& lsst::afw::geom::ellipses::BaseCore::Transformer::input

input core to be transformed

Definition at line 75 of file Transformer.h.

transform

lsst::geom::LinearTransform const& lsst::afw::geom::ellipses::BaseCore::Transformer::transform

transform object

Definition at line 76 of file Transformer.h.

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

• /j/snowflake/release/lsstsw/stack/Linux64/afw/19.0.0-4-ga671dab3b+1/include/lsst/afw/geom/ellipses/Transformer.h
• /j/snowflake/release/lsstsw/stack/Linux64/afw/19.0.0-4-ga671dab3b+1/src/geom/ellipses/Transformer.cc