An algorithm that fits a 2-component shapelet approximation to the PSF model. More...

#include <DoubleShapeletPsfApprox.h>

Inheritance diagram for lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm:

Public Types
typedef DoubleShapeletPsfApproxControl	Control

Public Member Functions
	DoubleShapeletPsfApproxAlgorithm (Control const &ctrl, std::string const &name, afw::table::Schema &schema)
	Failure modes passed by MeasurementErrors thrown by this class. More...

void	measure (afw::table::SourceRecord &measRecord, afw::image::Exposure< float > const &exposure) const
	Run all fitting stages on the Psf attached to the given Exposure, saving the results in measRecord. More...

void	fail (afw::table::SourceRecord &measRecord, lsst::meas::base::MeasurementError *error=nullptr) const
	Handle failures caught by the measurement plugin system, setting failure flags as appropriate. More...

virtual void	measureForced (afw::table::SourceRecord &measRecord, afw::image::Exposure< float > const &exposure, afw::table::SourceRecord const &refRecord, afw::geom::SkyWcs const &refWcs) const
	Called to measure a single child source in an image. More...

virtual void	measureNForced (afw::table::SourceCatalog const &measCat, afw::image::Exposure< float > const &exposure, afw::table::SourceCatalog const &refRecord, afw::geom::SkyWcs const &refWcs) const
	Called to simultaneously measure all children in a deblend family, in a single image. More...

virtual void	measureN (afw::table::SourceCatalog const &measCat, afw::image::Exposure< float > const &exposure) const
	Called to simultaneously measure all children in a deblend family, in a single image. More...

std::string	getLogName () const

Static Public Member Functions
static base::FlagDefinitionList const &	getFlagDefinitions ()

static shapelet::MultiShapeletFunction	initializeResult (Control const &ctrl)
	Create a MultiShapeletFunction with orders and radii and amplitude ratios from the control object. More...

static void	fitMoments (shapelet::MultiShapeletFunction &result, Control const &ctrl, afw::image::Image< Scalar > const &psfImage)
	Update a MultiShapeletFunction's ellipses to match the first and second moments of a PSF image. More...

static std::shared_ptr< OptimizerObjective >	makeObjective (afw::geom::ellipses::Ellipse const &moments, Control const &ctrl, afw::image::Image< Scalar > const &psfImage)
	Return an Objective object that can be used to fit the profile of the model. More...

static void	fitProfile (shapelet::MultiShapeletFunction &result, Control const &ctrl, afw::image::Image< Scalar > const &psfImage)
	Update a MultiShapeletFunction's zeroth-order profile by fitting radii and amplitudes. More...

static void	fitShapelets (shapelet::MultiShapeletFunction &result, Control const &ctrl, afw::image::Image< Scalar > const &psfImage)
	Update a MultiShapeletFunction's higher-order shapelet terms, holding everything else fixed. More...

Static Public Attributes
static base::FlagDefinition const	FAILURE

static base::FlagDefinition const	INVALID_POINT_FOR_PSF

static base::FlagDefinition const	INVALID_MOMENTS

static base::FlagDefinition const	MAX_ITERATIONS

Protected Attributes
std::string	_logName

Detailed Description

An algorithm that fits a 2-component shapelet approximation to the PSF model.

This algorithm fits a similar model to the one that has been used on the HSC side for several data releases, but uses the improved optimizer in meas_modelfit instead of the one in (the now defunct) meas_extensions_multiShapelet and using moments to reduce the number of parameters in the fit. It is faster and more robust than GeneralShapeletPsfApprox, but much less flexible.

The model is not a fully general one, even for two shapelet components. We tie the ellipticities of the two components together, hold the center fixed, and keep their radii fixed at a value set in the configuration; this means we fit only one set of ellipse parameters, instead of two.

Definition at line 96 of file DoubleShapeletPsfApprox.h.

Member Typedef Documentation

◆ Control

typedef DoubleShapeletPsfApproxControl lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::Control

Definition at line 106 of file DoubleShapeletPsfApprox.h.

Constructor & Destructor Documentation

◆ DoubleShapeletPsfApproxAlgorithm()

lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::DoubleShapeletPsfApproxAlgorithm	(	Control const &	ctrl,
		std::string const &	name,
		afw::table::Schema &	schema
	)

Failure modes passed by MeasurementErrors thrown by this class.

Construct an algorithm for use with record outputs.

Essentially all of the functionality of this class is accessible through static methods, so an instance only needs to be constructed if you want to store the results in a record object.

Parameters

[in]	ctrl	Control object specifying the details of the model and how to fit it.
[in]	name	Name of the algorithm; will be used as the prefix for all field names.
[in,out]	schema	Schema to which fields will be added. Must already contain a slot_Centroid alias pointing to fields with position information.

Member Function Documentation

◆ fail()

void lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::fail	(	afw::table::SourceRecord &	measRecord,
		lsst::meas::base::MeasurementError *	error = `nullptr`
	)		const

virtual

Handle failures caught by the measurement plugin system, setting failure flags as appropriate.

Implements lsst::meas::base::BaseAlgorithm.

◆ fitMoments()

static void lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::fitMoments	(	shapelet::MultiShapeletFunction &	result,
		Control const &	ctrl,
		afw::image::Image< Scalar > const &	psfImage
	)

static

Update a MultiShapeletFunction's ellipses to match the first and second moments of a PSF image.

The relative ampltidues, radii, and ellipticities of the ellipses will not be modified; both ellipses will simply be transformed (together) such that the moments of the MultiShapeletFunction match the (unweighted) moments of the image, and the two components will be scaled together to match the total flux in the image.

Parameters

[in,out]	result	MultiShapeletFunction to update. Must have unit circle moments. Probably the result of a call to initializeResult().
[in]	ctrl	Control object specifying the details of the model and how to fit it.
[in]	psfImage	Image of the PSF to fit. Should have xy0 set such that (0,0) is at the center of the image. Probably the result of a call to Psf::computeKernelImage().

Exceptions

meas::base::MeasurementError if the resulting moments are invalid, either because they have negative determinant or the radii are out of bounds.

◆ fitProfile()

static void lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::fitProfile	(	shapelet::MultiShapeletFunction &	result,
		Control const &	ctrl,
		afw::image::Image< Scalar > const &	psfImage
	)

static

Update a MultiShapeletFunction's zeroth-order profile by fitting radii and amplitudes.

Holding the center positions and ellipticities fixed, the radii and amplitudes of the two Gaussians are fit simultaneously with an optimizer. Higher-order terms will be ignored.

Parameters

[in,out]	result	MultiShapeletFunction to update. Probably the result of a call to fitMoments().
[in]	ctrl	Control object specifying the details of the model and how to fit it.
[in]	psfImage	Image of the PSF to fit. Should have xy0 set such that (0,0) is at the center of the image. Probably the result of a call to Psf::computeKernelImage().

◆ fitShapelets()

static void lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::fitShapelets	(	shapelet::MultiShapeletFunction &	result,
		Control const &	ctrl,
		afw::image::Image< Scalar > const &	psfImage
	)

static

Update a MultiShapeletFunction's higher-order shapelet terms, holding everything else fixed.

All ellipse parameters and the zeroth-order (Gaussian) shapelet coefficients will be held fixed.

Parameters

[in,out]	result	MultiShapeletFunction to update. Probably the result of a call to fitProfile().
[in]	ctrl	Control object specifying the details of the model and how to fit it.
[in]	psfImage	Image of the PSF to fit. Should have xy0 set such that (0,0) is at the center of the image. Probably the result of a call to Psf::computeKernelImage().

◆ getFlagDefinitions()

static base::FlagDefinitionList const& lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::getFlagDefinitions ( )

static

◆ getLogName()

std::string lsst::meas::base::BaseAlgorithm::getLogName ( ) const

inlineinherited

Definition at line 66 of file Algorithm.h.

66 { return _logName; }

lsst::meas::base::BaseAlgorithm::_logName

std::string _logName

Definition: Algorithm.h:69

◆ initializeResult()

static shapelet::MultiShapeletFunction lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::initializeResult ( Control const & ctrl )

static

Create a MultiShapeletFunction with orders and radii and amplitude ratios from the control object.

This creates a circular two-component MultiShapeletFunction with unit total flux and unit circle moments, with zeroth-order amplitudes matching ctrl.peakRatio and ellipse radii matching ctrl.radiusRatio.

◆ makeObjective()

static std::shared_ptr<OptimizerObjective> lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::makeObjective	(	afw::geom::ellipses::Ellipse const &	moments,
		Control const &	ctrl,
		afw::image::Image< Scalar > const &	psfImage
	)

static

Return an Objective object that can be used to fit the profile of the model.

By "profile" we mean the two radii and two zeroth-order amplitudes, which we fit in fitProfile() while holding all other parameters fixed.

This function is probably not useful to most users, who should just call fitProfile instead; it's public mostly to make it easier to test functionality internal to fitProfile().

The parameters expected by the Objective are:

The zeroth-order amplitude of the inner component.
The zeroth-order amplitude of the outer component.
The determinant radius of the inner component relative to the determinant radius of the moments ellipse.
The determinant radius of the outer component relative to the determinant radius of the moments ellipse.

Parameters

[in]	moments	Ellipse computed from the moments of the MultiShapeletFunction to be fit.
[in]	ctrl	Control object specifying the details of the model and how to fit it.
[in]	psfImage	Image of the PSF to fit. Should have xy0 set such that (0,0) is at the center of the image. Probably the result of a call to Psf::computeKernelImage().

◆ measure()

void lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::measure	(	afw::table::SourceRecord &	measRecord,
		afw::image::Exposure< float > const &	exposure
	)		const

virtual

Run all fitting stages on the Psf attached to the given Exposure, saving the results in measRecord.

We first call fitMoments(), then fitProfile(), then fitShapelets().

Implements lsst::meas::base::SingleFrameAlgorithm.

◆ measureForced()

virtual void lsst::meas::base::SimpleAlgorithm::measureForced	(	afw::table::SourceRecord &	measRecord,
		afw::image::Exposure< float > const &	exposure,
		afw::table::SourceRecord const &	refRecord,
		afw::geom::SkyWcs const &	refWcs
	)		const

inlinevirtualinherited

Called to measure a single child source in an image.

Before this method is called, all neighbors will be replaced with noise, using the outputs of the deblender. Outputs should be saved in the given SourceRecord, which can also be used to obtain centroid (see SafeCentroidExtractor) and shape (see SafeShapeExtractor) information.

Implements lsst::meas::base::ForcedAlgorithm.

Reimplemented in lsst::meas::extensions::photometryKron::KronFluxAlgorithm.

Definition at line 172 of file Algorithm.h.

                                                                   {
         measure(measRecord, exposure);
     }

◆ measureN()

void lsst::meas::base::SingleFrameAlgorithm::measureN	(	afw::table::SourceCatalog const &	measCat,
		afw::image::Exposure< float > const &	exposure
	)		const

virtualinherited

Called to simultaneously measure all children in a deblend family, in a single image.

Outputs should be saved in the given SourceCatalog, which can also be used to obtain centroid (see SafeCentroidExtractor) and shape (see SafeShapeExtractor) information.

The default implementation simply throws an exception, indicating that simultaneous measurement is not supported.

Definition at line 31 of file Algorithm.cc.

                                                                                    {
     throw LSST_EXCEPT(pex::exceptions::LogicError, "measureN not implemented for this algorithm");
 }

◆ measureNForced()

virtual void lsst::meas::base::SimpleAlgorithm::measureNForced	(	afw::table::SourceCatalog const &	measCat,
		afw::image::Exposure< float > const &	exposure,
		afw::table::SourceCatalog const &	refRecord,
		afw::geom::SkyWcs const &	refWcs
	)		const

inlinevirtualinherited

Called to simultaneously measure all children in a deblend family, in a single image.

Outputs should be saved in the given SourceCatalog, which can also be used to obtain centroid (see SafeCentroidExtractor) and shape (see SafeShapeExtractor) information.

The default implementation simply throws an exception, indicating that simultaneous measurement is not supported.

Reimplemented from lsst::meas::base::ForcedAlgorithm.

Definition at line 179 of file Algorithm.h.

                                                                    {
         measureN(measCat, exposure);
     }

Member Data Documentation

◆ _logName

std::string lsst::meas::base::BaseAlgorithm::_logName

protectedinherited

Definition at line 69 of file Algorithm.h.

◆ FAILURE

base::FlagDefinition const lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::FAILURE

static

Definition at line 101 of file DoubleShapeletPsfApprox.h.

◆ INVALID_MOMENTS

base::FlagDefinition const lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::INVALID_MOMENTS

static

Definition at line 103 of file DoubleShapeletPsfApprox.h.

◆ INVALID_POINT_FOR_PSF

base::FlagDefinition const lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::INVALID_POINT_FOR_PSF

static

Definition at line 102 of file DoubleShapeletPsfApprox.h.

◆ MAX_ITERATIONS

base::FlagDefinition const lsst::meas::modelfit::DoubleShapeletPsfApproxAlgorithm::MAX_ITERATIONS

static

Definition at line 104 of file DoubleShapeletPsfApprox.h.

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

/j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/meas_modelfit/22.0.1-4-g44f2e3d+9e4ab0f4fa/include/lsst/meas/modelfit/DoubleShapeletPsfApprox.h

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Attributes

Detailed Description

Member Typedef Documentation

◆ Control

Constructor & Destructor Documentation

◆ DoubleShapeletPsfApproxAlgorithm()

Member Function Documentation

◆ fail()

◆ fitMoments()

◆ fitProfile()

◆ fitShapelets()

◆ getFlagDefinitions()

◆ getLogName()

◆ initializeResult()

◆ makeObjective()

◆ measure()

◆ measureForced()

◆ measureN()

◆ measureNForced()

Member Data Documentation

◆ _logName

◆ FAILURE

◆ INVALID_MOMENTS

◆ INVALID_POINT_FOR_PSF

◆ MAX_ITERATIONS