lsst::meas::astrom::SipTransformBase Class Reference

Base class for SIP transform objects. More...

#include <SipTransform.h>

Inheritance diagram for lsst::meas::astrom::SipTransformBase:

Public Member Functions
geom::Point2D const &	getPixelOrigin () const
	Return the pixel origin (CRPIX, but zero-indexed) of the transform. More...
geom::LinearTransform const &	getCdMatrix () const
	Return the CD matrix of the transform. More...
PolynomialTransform const &	getPoly () const
	Return the polynomial component of the transform (A,B) or (AP,BP). More...

Protected Member Functions
	SipTransformBase (geom::Point2D const &pixelOrigin, geom::LinearTransform const &cdMatrix, PolynomialTransform const &poly)
	Construct a SipTransformBase from its components. More...
	SipTransformBase (SipTransformBase const &other)=default
	SipTransformBase (SipTransformBase &&other)=default
SipTransformBase &	operator= (SipTransformBase const &other)=default
SipTransformBase &	operator= (SipTransformBase &&other)=default
void	swap (SipTransformBase &other)
void	transformPixelsInPlace (geom::AffineTransform const &s)

Protected Attributes
geom::Point2D	_pixelOrigin
geom::LinearTransform	_cdMatrix
PolynomialTransform	_poly

Detailed Description

Base class for SIP transform objects.

This class simply provides some getters for its derived classes. It should not be used directly, and does not define a polymorphic interface.

Definition at line 46 of file SipTransform.h.

Constructor & Destructor Documentation

SipTransformBase() [1/3]

lsst::meas::astrom::SipTransformBase::SipTransformBase ( geom::Point2D const &  pixelOrigin, geom::LinearTransform const &  cdMatrix, PolynomialTransform const &  poly  )

inlineprotected

Construct a SipTransformBase from its components.

See SipForwardTransform and SipReverseTransform for more extensive definitions.

Parameters

[in]	pixelOrigin	CRPIX \((u_0,v_0)\) (zero-indexed)
[in]	cdMatrix	CD matrix \(Z\)
[in]	poly	Either the forward or reverse SIP polynomial (depending on the derived class).

Definition at line 76 of file SipTransform.h.

            : _pixelOrigin(pixelOrigin), _cdMatrix(cdMatrix), _poly(poly) {}

SipTransformBase() [2/3]

lsst::meas::astrom::SipTransformBase::SipTransformBase ( SipTransformBase const &  other )

protecteddefault

SipTransformBase() [3/3]

lsst::meas::astrom::SipTransformBase::SipTransformBase ( SipTransformBase &&  other )

protecteddefault

Member Function Documentation

getCdMatrix()

geom::LinearTransform const& lsst::meas::astrom::SipTransformBase::getCdMatrix ( ) const

inline

Return the CD matrix of the transform.

Definition at line 56 of file SipTransform.h.

{ return _cdMatrix; }

getPixelOrigin()

geom::Point2D const& lsst::meas::astrom::SipTransformBase::getPixelOrigin ( ) const

inline

Return the pixel origin (CRPIX, but zero-indexed) of the transform.

Definition at line 51 of file SipTransform.h.

{ return _pixelOrigin; }

getPoly()

PolynomialTransform const& lsst::meas::astrom::SipTransformBase::getPoly ( ) const

inline

Return the polynomial component of the transform (A,B) or (AP,BP).

Definition at line 61 of file SipTransform.h.

{ return _poly; }

operator=() [1/2]

SipTransformBase& lsst::meas::astrom::SipTransformBase::operator= ( SipTransformBase const &  other )

protecteddefault

operator=() [2/2]

SipTransformBase& lsst::meas::astrom::SipTransformBase::operator= ( SipTransformBase &&  other )

protecteddefault

swap()

void lsst::meas::astrom::SipTransformBase::swap ( SipTransformBase &  other )

inlineprotected

Definition at line 85 of file SipTransform.h.

                                       {
        std::swap(_pixelOrigin, other._pixelOrigin);
        std::swap(_cdMatrix, other._cdMatrix);
        _poly.swap(other._poly);
    }

transformPixelsInPlace()

void lsst::meas::astrom::SipTransformBase::transformPixelsInPlace ( geom::AffineTransform const &  s )

protected

Definition at line 40 of file SipTransform.cc.

                                                                          {
    // The implementation for transformPixels is identical for
    // SipForwardTransform and SipReverseTransform.  That's pretty obvious for
    // the pixel origin and CD matrix, which are the same in both cases, but
    // it wasn't obvious to me until I did the math that the polynomial
    // transforms are composed with the affine transform the same way.
    auto sInv = s.inverted();
    _pixelOrigin = s.getLinear()(_pixelOrigin - sInv.getTranslation());
    _cdMatrix = _cdMatrix * sInv.getLinear();
    _poly = compose(s.getLinear(), compose(getPoly(), sInv.getLinear()));
}

Member Data Documentation

_cdMatrix

geom::LinearTransform lsst::meas::astrom::SipTransformBase::_cdMatrix

protected

Definition at line 94 of file SipTransform.h.

_pixelOrigin

geom::Point2D lsst::meas::astrom::SipTransformBase::_pixelOrigin

protected

Definition at line 93 of file SipTransform.h.

_poly

PolynomialTransform lsst::meas::astrom::SipTransformBase::_poly

protected

Definition at line 95 of file SipTransform.h.

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

• /j/snowflake/release/lsstsw/stack/Linux64/meas_astrom/17.0.1-9-gc4bbfb2+3/include/lsst/meas/astrom/SipTransform.h
• /j/snowflake/release/lsstsw/stack/Linux64/meas_astrom/17.0.1-9-gc4bbfb2+3/src/SipTransform.cc