lsst::shapelet::ShapeletFunction Class Reference

A 2-d function defined by an expansion onto a Gauss-Laguerre or Gauss-Hermite basis. More...

#include <ShapeletFunction.h>

Public Types
typedef std::shared_ptr< ShapeletFunction >	Ptr
typedef std::shared_ptr< ShapeletFunction const >	ConstPtr
typedef ShapeletFunctionEvaluator	Evaluator

Public Member Functions
int	getOrder () const
	Return the maximum order (inclusive), either \(n_x + n_y\) or \(p + q\).
afw::geom::ellipses::Ellipse const &	getEllipse () const
	Get the ellipse (const).
afw::geom::ellipses::Ellipse &	getEllipse ()
	Get the ellipse (non-const).
void	setEllipse (afw::geom::ellipses::Ellipse const &ellipse)
	Set the ellipse.
BasisTypeEnum	getBasisType () const
	Return the basis type (HERMITE or LAGUERRE).
void	changeBasisType (BasisTypeEnum basisType)
	Change the basis type and convert coefficients in-place correspondingly.
void	normalize (double value=1.0)
	Normalize the integral of the shapelet function to the given value.
ndarray::Array< double, 1, 1 > const	getCoefficients ()
	Return the coefficient vector.
ndarray::Array< double const, 1, 1 > const	getCoefficients () const
	Return the coefficient vector (const).
ShapeletFunction	convolve (ShapeletFunction const &other) const
	Convolve the shapelet function.
Evaluator	evaluate () const
	Construct a helper object that can efficiently evaluate the function.
void	shiftInPlace (geom::Extent2D const &offset)
	Shift the shapelet function by shifting the basis ellipse.
void	transformInPlace (geom::AffineTransform const &transform)
	Transform the shapelet function by transforming the basis ellipse.
	ShapeletFunction (int order, BasisTypeEnum basisType)
	Construct a function with a unit-circle ellipse and set all coefficients to zero.
	ShapeletFunction (int order, BasisTypeEnum basisType, ndarray::Array< double, 1, 1 > const &coefficients)
	Construct a function with a unit-circle ellipse and a deep-copied coefficient vector.
	ShapeletFunction (int order, BasisTypeEnum basisType, double radius, geom::Point2D const &center=geom::Point2D())
	Construct a function with a circular ellipse and set all coefficients to zero.
	ShapeletFunction (int order, BasisTypeEnum basisType, double radius, geom::Point2D const &center, ndarray::Array< double, 1, 1 > const &coefficients)
	Construct a function with a circular ellipse and a deep-copied coefficient vector.
	ShapeletFunction (int order, BasisTypeEnum basisType, afw::geom::ellipses::Ellipse const &ellipse)
	Construct a function and set all coefficients to zero.
	ShapeletFunction (int order, BasisTypeEnum basisType, afw::geom::ellipses::Ellipse const &ellipse, ndarray::Array< double const, 1, 1 > const &coefficients)
	Construct a function with a deep-copied coefficient vector.
	ShapeletFunction (ShapeletFunction const &other)
	Copy constructor (deep).
ShapeletFunction &	operator= (ShapeletFunction const &other)
	Assignment (deep).
	ShapeletFunction ()
	Default constructor to appease SWIG (used by std::list). Not for use by users.

Static Public Attributes
static double const	FLUX_FACTOR

Detailed Description

A 2-d function defined by an expansion onto a Gauss-Laguerre or Gauss-Hermite basis.

The coefficients are in units of flux, not surface brightness; increasing the area of the basis ellipse while leaving the coefficients unchanged will decrease the surface brightness by the ratio of the areas of the new and old ellipses. This convention is necessary to ensure that convolution with a delta function is sane. Because the BasisEvaluator class does not deal with ellipses, it is necessary to divide its output by R^2 to get the same result as a ShapeletFunctionEvaluator whose ellipse has determinant radius of R.

The coefficient normalization is not identical to that of a Gaussian, however; a zeroth-order ShapeletFunction with its only coefficient value set to 1 has a flux of 2.0 * pi^(1/2). This value is defined as ShapeletFunction::FLUX_FACTOR. Of course, to get the flux of a more complex shapelet expansion you have to use ShapeletFunctionEvaluator::integrate().

Note that the units of the coefficients would have to be radius for basis functions with the same ellipse to be orthonormal, but this orthonormality isn't very useful, because the basis functions aren't even orthogonal in the more common case that the ellipses differ. However, basis functions defined on the unit circle are still orthonormal.

Definition at line 65 of file ShapeletFunction.h.

Member Typedef Documentation

ConstPtr

typedef std::shared_ptr<ShapeletFunction const> lsst::shapelet::ShapeletFunction::ConstPtr

Definition at line 69 of file ShapeletFunction.h.

Evaluator

typedef ShapeletFunctionEvaluator lsst::shapelet::ShapeletFunction::Evaluator

Definition at line 71 of file ShapeletFunction.h.

Ptr

typedef std::shared_ptr<ShapeletFunction> lsst::shapelet::ShapeletFunction::Ptr

Definition at line 68 of file ShapeletFunction.h.

Constructor & Destructor Documentation

ShapeletFunction() [1/8]

lsst::shapelet::ShapeletFunction::ShapeletFunction	(	int	order,
		BasisTypeEnum	basisType )

Construct a function with a unit-circle ellipse and set all coefficients to zero.

ShapeletFunction() [2/8]

lsst::shapelet::ShapeletFunction::ShapeletFunction	(	int	order,
		BasisTypeEnum	basisType,
		ndarray::Array< double, 1, 1 > const &	coefficients )

Construct a function with a unit-circle ellipse and a deep-copied coefficient vector.

ShapeletFunction() [3/8]

lsst::shapelet::ShapeletFunction::ShapeletFunction	(	int	order,
		BasisTypeEnum	basisType,
		double	radius,
		geom::Point2D const &	center = geom::Point2D() )

Construct a function with a circular ellipse and set all coefficients to zero.

ShapeletFunction() [4/8]

lsst::shapelet::ShapeletFunction::ShapeletFunction	(	int	order,
		BasisTypeEnum	basisType,
		double	radius,
		geom::Point2D const &	center,
		ndarray::Array< double, 1, 1 > const &	coefficients )

Construct a function with a circular ellipse and a deep-copied coefficient vector.

ShapeletFunction() [5/8]

lsst::shapelet::ShapeletFunction::ShapeletFunction	(	int	order,
		BasisTypeEnum	basisType,
		afw::geom::ellipses::Ellipse const &	ellipse )

Construct a function and set all coefficients to zero.

ShapeletFunction() [6/8]

lsst::shapelet::ShapeletFunction::ShapeletFunction	(	int	order,
		BasisTypeEnum	basisType,
		afw::geom::ellipses::Ellipse const &	ellipse,
		ndarray::Array< double const, 1, 1 > const &	coefficients )

Construct a function with a deep-copied coefficient vector.

ShapeletFunction() [7/8]

lsst::shapelet::ShapeletFunction::ShapeletFunction

(

ShapeletFunction const &

other

)

Copy constructor (deep).

ShapeletFunction() [8/8]

lsst::shapelet::ShapeletFunction::ShapeletFunction

(

)

Default constructor to appease SWIG (used by std::list). Not for use by users.

Member Function Documentation

changeBasisType()

void lsst::shapelet::ShapeletFunction::changeBasisType ( BasisTypeEnum basisType )

inline

Change the basis type and convert coefficients in-place correspondingly.

Definition at line 91 of file ShapeletFunction.h.

                                                  {
        ConversionMatrix::convertCoefficientVector(_coefficients, _basisType, basisType, _order);
        _basisType = basisType;
    }

convolve()

ShapeletFunction lsst::shapelet::ShapeletFunction::convolve

(

ShapeletFunction const &

other

)

const

Convolve the shapelet function.

evaluate()

ShapeletFunctionEvaluator lsst::shapelet::ShapeletFunction::evaluate ( ) const

inline

Construct a helper object that can efficiently evaluate the function.

Definition at line 241 of file ShapeletFunction.h.

                                                                  {
    return ShapeletFunctionEvaluator(*this);
}

getBasisType()

BasisTypeEnum lsst::shapelet::ShapeletFunction::getBasisType ( ) const

inline

Return the basis type (HERMITE or LAGUERRE).

Definition at line 88 of file ShapeletFunction.h.

{ return _basisType; }

getCoefficients() [1/2]

ndarray::Array< double, 1, 1 > const lsst::shapelet::ShapeletFunction::getCoefficients ( )

inline

Return the coefficient vector.

Definition at line 100 of file ShapeletFunction.h.

{ return _coefficients; }

getCoefficients() [2/2]

ndarray::Array< double const, 1, 1 > const lsst::shapelet::ShapeletFunction::getCoefficients ( ) const

inline

Return the coefficient vector (const).

Definition at line 103 of file ShapeletFunction.h.

{ return _coefficients; }

getEllipse() [1/2]

afw::geom::ellipses::Ellipse & lsst::shapelet::ShapeletFunction::getEllipse ( )

inline

Get the ellipse (non-const).

Definition at line 82 of file ShapeletFunction.h.

{ return _ellipse; }

getEllipse() [2/2]

afw::geom::ellipses::Ellipse const & lsst::shapelet::ShapeletFunction::getEllipse ( ) const

inline

Get the ellipse (const).

Definition at line 79 of file ShapeletFunction.h.

{ return _ellipse; }

getOrder()

int lsst::shapelet::ShapeletFunction::getOrder ( ) const

inline

Return the maximum order (inclusive), either \(n_x + n_y\) or \(p + q\).

Definition at line 76 of file ShapeletFunction.h.

{ return _order; }

normalize()

void lsst::shapelet::ShapeletFunction::normalize

(

double

value = 1.0

)

Normalize the integral of the shapelet function to the given value.

operator=()

ShapeletFunction & lsst::shapelet::ShapeletFunction::operator=

(

ShapeletFunction const &

other

)

Assignment (deep).

setEllipse()

void lsst::shapelet::ShapeletFunction::setEllipse ( afw::geom::ellipses::Ellipse const & ellipse )

inline

Set the ellipse.

Definition at line 85 of file ShapeletFunction.h.

{ _ellipse = ellipse; }

shiftInPlace()

void lsst::shapelet::ShapeletFunction::shiftInPlace ( geom::Extent2D const & offset )

inline

Shift the shapelet function by shifting the basis ellipse.

Definition at line 112 of file ShapeletFunction.h.

                                                   {
        _ellipse.getCenter() += offset;
    }

transformInPlace()

void lsst::shapelet::ShapeletFunction::transformInPlace ( geom::AffineTransform const & transform )

inline

Transform the shapelet function by transforming the basis ellipse.

Definition at line 117 of file ShapeletFunction.h.

                                                                 {
        _ellipse.transform(transform).inPlace();
    }

Member Data Documentation

FLUX_FACTOR

double const lsst::shapelet::ShapeletFunction::FLUX_FACTOR

static

Definition at line 73 of file ShapeletFunction.h.

---

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/shapelet/ge79ae78c31+0e5473021a/include/lsst/shapelet/ShapeletFunction.h