lsst::afw::geom::ellipses::Ellipse::GridTransform Class Reference

A temporary-only expression object representing an lsst::geom::AffineTransform that maps the Ellipse to a unit circle at the origin. More...

#include <GridTransform.h>

Public Types
typedef Eigen::Matrix< double, 6, 5 >	DerivativeMatrix
	Matrix type for derivative with respect to input ellipse parameters. More...

Public Member Functions
	GridTransform (Ellipse const &input)
	Standard constructor. More...
lsst::geom::AffineTransform::Matrix	getMatrix () const
	Return the transform matrix as an Eigen object. More...
DerivativeMatrix	d () const
	Return the derivative of transform with respect to input ellipse. More...
double	getDeterminant () const
	Return the determinant of the lsst::geom::AffineTransform. More...
	operator lsst::geom::AffineTransform () const
	Convert the proxy to an lsst::geom::AffineTransform. More...
lsst::geom::AffineTransform	inverted () const
	Return the inverse of the AffineTransform. More...

Detailed Description

A temporary-only expression object representing an lsst::geom::AffineTransform that maps the Ellipse to a unit circle at the origin.

Definition at line 82 of file GridTransform.h.

Member Typedef Documentation

DerivativeMatrix

typedef Eigen::Matrix<double, 6, 5> lsst::afw::geom::ellipses::Ellipse::GridTransform::DerivativeMatrix

Matrix type for derivative with respect to input ellipse parameters.

Definition at line 85 of file GridTransform.h.

Constructor & Destructor Documentation

GridTransform()

lsst::afw::geom::ellipses::Ellipse::GridTransform::GridTransform ( Ellipse const &  input )

explicit

Standard constructor.

Definition at line 100 of file GridTransform.cc.

: _input(input), _coreGt(input.getCore()) {}

Member Function Documentation

d()

Ellipse::GridTransform::DerivativeMatrix lsst::afw::geom::ellipses::Ellipse::GridTransform::d

(

)

const

Return the derivative of transform with respect to input ellipse.

Definition at line 110 of file GridTransform.cc.

                                                                   {
    DerivativeMatrix r = DerivativeMatrix::Zero();
    lsst::geom::LinearTransform linear = _coreGt;
    r.block<4, 3>(0, 0) = _coreGt.d();
    double x = -_input.getCenter().getX();
    double y = -_input.getCenter().getY();
    r(lsst::geom::AffineTransform::X, Ellipse::X) = -linear[lsst::geom::LinearTransform::XX];
    r(lsst::geom::AffineTransform::Y, Ellipse::X) = -linear[lsst::geom::LinearTransform::YX];
    r(lsst::geom::AffineTransform::X, Ellipse::Y) = -linear[lsst::geom::LinearTransform::XY];
    r(lsst::geom::AffineTransform::Y, Ellipse::Y) = -linear[lsst::geom::LinearTransform::YY];
    r(lsst::geom::AffineTransform::X, 0) =
            x * r(lsst::geom::AffineTransform::XX, 0) + y * r(lsst::geom::AffineTransform::XY, 0);
    r(lsst::geom::AffineTransform::Y, 0) =
            x * r(lsst::geom::AffineTransform::YX, 0) + y * r(lsst::geom::AffineTransform::YY, 0);
    r(lsst::geom::AffineTransform::X, 1) =
            x * r(lsst::geom::AffineTransform::XX, 1) + y * r(lsst::geom::AffineTransform::XY, 1);
    r(lsst::geom::AffineTransform::Y, 1) =
            x * r(lsst::geom::AffineTransform::YX, 1) + y * r(lsst::geom::AffineTransform::YY, 1);
    r(lsst::geom::AffineTransform::X, 2) =
            x * r(lsst::geom::AffineTransform::XX, 2) + y * r(lsst::geom::AffineTransform::XY, 2);
    r(lsst::geom::AffineTransform::Y, 2) =
            x * r(lsst::geom::AffineTransform::YX, 2) + y * r(lsst::geom::AffineTransform::YY, 2);
    return r;
}

getDeterminant()

double lsst::afw::geom::ellipses::Ellipse::GridTransform::getDeterminant

(

)

const

Return the determinant of the lsst::geom::AffineTransform.

Definition at line 135 of file GridTransform.cc.

{ return _coreGt.getDeterminant(); }

getMatrix()

lsst::geom::AffineTransform::Matrix lsst::afw::geom::ellipses::Ellipse::GridTransform::getMatrix

(

)

const

Return the transform matrix as an Eigen object.

Definition at line 102 of file GridTransform.cc.

                                                                    {
    lsst::geom::AffineTransform::Matrix r = lsst::geom::AffineTransform::Matrix::Zero();
    r.block<2, 2>(0, 0) = _coreGt.getMatrix();
    r.block<2, 1>(0, 2) = -r.block<2, 2>(0, 0) * _input.getCenter().asEigen();
    r(2, 2) = 1.0;
    return r;
}

inverted()

lsst::geom::AffineTransform lsst::afw::geom::ellipses::Ellipse::GridTransform::inverted

(

)

const

Return the inverse of the AffineTransform.

Definition at line 142 of file GridTransform.cc.

                                                             {
    return lsst::geom::AffineTransform(_coreGt.inverted(), lsst::geom::Extent2D(_input.getCenter()));
}

operator lsst::geom::AffineTransform()

lsst::afw::geom::ellipses::Ellipse::GridTransform::operator lsst::geom::AffineTransform

(

)

const

Convert the proxy to an lsst::geom::AffineTransform.

Definition at line 137 of file GridTransform.cc.

                                                             {
    lsst::geom::LinearTransform linear = _coreGt;
    return lsst::geom::AffineTransform(linear, linear(lsst::geom::Point2D() - _input.getCenter()));
}

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

• /j/snowflake/release/lsstsw/stack/0.4.3/Linux64/afw/21.0.0-25-g1d57be3cd+e73869a214/include/lsst/afw/geom/ellipses/GridTransform.h
• /j/snowflake/release/lsstsw/stack/0.4.3/Linux64/afw/21.0.0-25-g1d57be3cd+e73869a214/src/geom/ellipses/GridTransform.cc