lsst::jointcal::PhotometryModel Class Reference

#include <PhotometryModel.h>

Inheritance diagram for lsst::jointcal::PhotometryModel:

Public Member Functions
	PhotometryModel (LOG_LOGGER log, double errorPedestal=0)
virtual Eigen::Index	assignIndices (std::string const &whatToFit, Eigen::Index firstIndex)=0
	Assign indices in the full matrix to the parameters being fit in the mappings, starting at firstIndex.
virtual void	offsetParams (Eigen::VectorXd const &delta)=0
	Offset the parameters by the provided amounts (by -delta).
virtual void	offsetFittedStar (FittedStar &fittedStar, double delta) const =0
	Offset the appropriate flux or magnitude (by -delta).
virtual double	computeResidual (CcdImage const &ccdImage, MeasuredStar const &measuredStar) const =0
	Compute the residual between the model applied to a star and its associated fittedStar.
virtual double	transform (CcdImage const &ccdImage, MeasuredStar const &measuredStar) const =0
	Return the on-sky transformed flux for measuredStar on ccdImage.
virtual double	transformError (CcdImage const &ccdImage, MeasuredStar const &measuredStar) const =0
	Return the on-sky transformed flux uncertainty for measuredStar on ccdImage.
virtual void	freezeErrorTransform ()=0
	Once this routine has been called, the error transform is not modified by offsetParams().
virtual void	getMappingIndices (CcdImage const &ccdImage, IndexVector &indices) const =0
	Get how this set of parameters (of length Npar()) map into the "grand" fit.
virtual void	computeParameterDerivatives (MeasuredStar const &measuredStar, CcdImage const &ccdImage, Eigen::VectorXd &derivatives) const =0
	Compute the parametric derivatives of this model.
virtual double	getRefError (RefStar const &refStar) const =0
	Return the refStar error appropriate for this model (e.g. fluxErr or magErr).
virtual double	computeRefResidual (FittedStar const &fittedStar, RefStar const &refStar) const =0
	Return the fittedStar - refStar residual appropriate for this model (e.g. flux - flux or mag - mag).
virtual std::shared_ptr< afw::image::PhotoCalib >	toPhotoCalib (CcdImage const &ccdImage) const =0
	Return the mapping of ccdImage represented as a PhotoCalib.
std::size_t	getNpar (CcdImage const &ccdImage) const
	Return the number of parameters in the mapping of CcdImage.
PhotometryMappingBase const &	getMapping (CcdImage const &ccdImage) const
	Get the mapping associated with ccdImage.
virtual std::size_t	getTotalParameters () const =0
	Return the total number of parameters in this model.
virtual void	print (std::ostream &out) const =0
	Print a string representation of the contents of this mapping, for debugging.
bool	validate (CcdImageList const &ccdImageList, int ndof) const
	Return true if this is a "reasonable" model.
bool	checkPositiveOnBBox (CcdImage const &ccdImage) const
	Check that the model is positive on the ccdImage bbox.
double	getErrorPedestal () const
double	tweakFluxError (jointcal::MeasuredStar const &measuredStar) const
	Add a fraction of the instrumental flux to the instrumental flux error, in quadrature.
double	tweakMagnitudeError (jointcal::MeasuredStar const &measuredStar) const
	Add a small magnitude offset to the "instrumental magnitude" error, in quadrature.
virtual	~PhotometryModel ()=default

Protected Member Functions
virtual PhotometryMappingBase *	findMapping (CcdImage const &ccdImage) const =0
	Return a pointer to the mapping associated with this ccdImage.

Protected Attributes
LOG_LOGGER	_log
	lsst.logging instance, to be created by a subclass so that messages have consistent name.
double	errorPedestal

Friends
std::ostream &	operator<< (std::ostream &s, PhotometryModel const &model)

Detailed Description

Definition at line 45 of file PhotometryModel.h.

Constructor & Destructor Documentation

PhotometryModel()

lsst::jointcal::PhotometryModel::PhotometryModel ( LOG_LOGGER log, double errorPedestal = 0 )

inline

Parameters

log	Logger to send messages to, to keep names consistent when logging.
errorPedestal	Pedestal on flux/magnitude error (percent of flux or delta magnitude).

Definition at line 51 of file PhotometryModel.h.

: _log(std::move(log)), errorPedestal(errorPedestal) {}

~PhotometryModel()

virtual lsst::jointcal::PhotometryModel::~PhotometryModel ( )

virtualdefault

Member Function Documentation

assignIndices()

virtual Eigen::Index lsst::jointcal::PhotometryModel::assignIndices ( std::string const & whatToFit, Eigen::Index firstIndex )

pure virtual

Assign indices in the full matrix to the parameters being fit in the mappings, starting at firstIndex.

Parameters

[in]	whatToFit	String containing parameters to fit.
[in]	firstIndex	Index to start assigning at.

Returns

The highest assigned index.

Implemented in lsst::jointcal::ConstrainedPhotometryModel, and lsst::jointcal::SimplePhotometryModel.

checkPositiveOnBBox()

bool lsst::jointcal::PhotometryModel::checkPositiveOnBBox

(

CcdImage const &

ccdImage

)

const

Check that the model is positive on the ccdImage bbox.

Parameters

ccdImage

The ccdImage to test.

Returns

True if the image is positive on a sampling of points of the ccdImage bbox.

Definition at line 49 of file PhotometryModel.cc.

                                                                        {
    bool check = true;
    auto bbox = ccdImage.getImageFrame();
    for (auto const &x : {bbox.xMin, bbox.getCenter().x, bbox.xMax})
        for (auto const &y : {bbox.yMin, bbox.getCenter().y, bbox.yMax}) {
            // flux, fluxErr, instFlux, instFluxErr all 1
            jointcal::MeasuredStar star(jointcal::BaseStar(x, y, 1, 1));
            star.setInstFluxAndErr(1, 1);
            double result = transform(ccdImage, star);
            // Don't short circuit so that we log every place the model is negative.
            if (result < 0) {
                LOGLS_WARN(_log, "CcdImage " << ccdImage.getName() << " is negative at (" << x << "," << y
                                             << "): " << result);
                check = false;
            }
        }
    return check;
}

computeParameterDerivatives()

virtual void lsst::jointcal::PhotometryModel::computeParameterDerivatives ( MeasuredStar const & measuredStar, CcdImage const & ccdImage, Eigen::VectorXd & derivatives ) const

pure virtual

Compute the parametric derivatives of this model.

Parameters

[in]	measuredStar	The measured star with the position and flux to compute at.
[in]	ccdImage	The ccdImage containing the measured star, to find the correct mapping.
[out]	derivatives	The computed derivatives. Must be pre-allocated to the correct size.

Implemented in lsst::jointcal::ConstrainedPhotometryModel, and lsst::jointcal::SimplePhotometryModel.

computeRefResidual()

virtual double lsst::jointcal::PhotometryModel::computeRefResidual ( FittedStar const & fittedStar, RefStar const & refStar ) const

pure virtual

Return the fittedStar - refStar residual appropriate for this model (e.g. flux - flux or mag - mag).

Implemented in lsst::jointcal::ConstrainedFluxModel, lsst::jointcal::ConstrainedMagnitudeModel, lsst::jointcal::SimpleFluxModel, and lsst::jointcal::SimpleMagnitudeModel.

computeResidual()

virtual double lsst::jointcal::PhotometryModel::computeResidual ( CcdImage const & ccdImage, MeasuredStar const & measuredStar ) const

pure virtual

Compute the residual between the model applied to a star and its associated fittedStar.

\[ residual = Model(measuredStar) - fittedStar \]

Parameters

ccdImage	The ccdImage where measuredStar resides.
measuredStar	The measured star position to compute the residual of.

Returns

The residual.

Implemented in lsst::jointcal::ConstrainedFluxModel, lsst::jointcal::ConstrainedMagnitudeModel, lsst::jointcal::SimpleFluxModel, and lsst::jointcal::SimpleMagnitudeModel.

findMapping()

virtual PhotometryMappingBase * lsst::jointcal::PhotometryModel::findMapping ( CcdImage const & ccdImage ) const

protectedpure virtual

Return a pointer to the mapping associated with this ccdImage.

Implemented in lsst::jointcal::ConstrainedPhotometryModel, and lsst::jointcal::SimplePhotometryModel.

freezeErrorTransform()

virtual void lsst::jointcal::PhotometryModel::freezeErrorTransform ( )

pure virtual

Once this routine has been called, the error transform is not modified by offsetParams().

The routine can be called when the mappings are roughly in place. After the call, the transformations used to propagate errors are no longer affected when updating the mappings. This allows an exactly linear fit, which can be necessary for some model+data combinations.

Implemented in lsst::jointcal::ConstrainedPhotometryModel, and lsst::jointcal::SimplePhotometryModel.

getErrorPedestal()

double lsst::jointcal::PhotometryModel::getErrorPedestal ( ) const

inline

Definition at line 197 of file PhotometryModel.h.

{ return errorPedestal; }

getMapping()

PhotometryMappingBase const & lsst::jointcal::PhotometryModel::getMapping ( CcdImage const & ccdImage ) const

inline

Get the mapping associated with ccdImage.

Definition at line 157 of file PhotometryModel.h.

                                                                            {
        return *(findMapping(ccdImage));
    }

getMappingIndices()

virtual void lsst::jointcal::PhotometryModel::getMappingIndices ( CcdImage const & ccdImage, IndexVector & indices ) const

pure virtual

Get how this set of parameters (of length Npar()) map into the "grand" fit.

Parameters

[in]	ccdImage	The ccdImage to look up.
[out]	indices	The indices of the mapping associated with ccdImage.

Implemented in lsst::jointcal::ConstrainedPhotometryModel, and lsst::jointcal::SimplePhotometryModel.

getNpar()

std::size_t lsst::jointcal::PhotometryModel::getNpar ( CcdImage const & ccdImage ) const

inline

Return the number of parameters in the mapping of CcdImage.

Definition at line 154 of file PhotometryModel.h.

{ return findMapping(ccdImage)->getNpar(); }

getRefError()

virtual double lsst::jointcal::PhotometryModel::getRefError ( RefStar const & refStar ) const

pure virtual

Return the refStar error appropriate for this model (e.g. fluxErr or magErr).

Implemented in lsst::jointcal::ConstrainedFluxModel, lsst::jointcal::ConstrainedMagnitudeModel, lsst::jointcal::SimpleFluxModel, and lsst::jointcal::SimpleMagnitudeModel.

getTotalParameters()

virtual std::size_t lsst::jointcal::PhotometryModel::getTotalParameters ( ) const

pure virtual

Return the total number of parameters in this model.

Implemented in lsst::jointcal::ConstrainedPhotometryModel, and lsst::jointcal::SimplePhotometryModel.

offsetFittedStar()

virtual void lsst::jointcal::PhotometryModel::offsetFittedStar ( FittedStar & fittedStar, double delta ) const

pure virtual

Offset the appropriate flux or magnitude (by -delta).

Parameters

fittedStar	The star to update.
delta	The amount to update by.

Implemented in lsst::jointcal::ConstrainedFluxModel, lsst::jointcal::ConstrainedMagnitudeModel, lsst::jointcal::SimpleFluxModel, and lsst::jointcal::SimpleMagnitudeModel.

offsetParams()

virtual void lsst::jointcal::PhotometryModel::offsetParams ( Eigen::VectorXd const & delta )

pure virtual

Offset the parameters by the provided amounts (by -delta).

The shifts are applied according to the indices given in assignIndices.

Parameters

[in]

delta

vector of offsets to apply

Implemented in lsst::jointcal::ConstrainedPhotometryModel, and lsst::jointcal::SimplePhotometryModel.

print()

virtual void lsst::jointcal::PhotometryModel::print ( std::ostream & out ) const

pure virtual

Print a string representation of the contents of this mapping, for debugging.

This string representation can be very verbose, as it contains all of the parameters of all of the transforms in this model.

Implemented in lsst::jointcal::ConstrainedPhotometryModel, lsst::jointcal::ConstrainedFluxModel, lsst::jointcal::ConstrainedMagnitudeModel, lsst::jointcal::SimplePhotometryModel, lsst::jointcal::SimpleFluxModel, and lsst::jointcal::SimpleMagnitudeModel.

toPhotoCalib()

virtual std::shared_ptr< afw::image::PhotoCalib > lsst::jointcal::PhotometryModel::toPhotoCalib ( CcdImage const & ccdImage ) const

pure virtual

Return the mapping of ccdImage represented as a PhotoCalib.

Implemented in lsst::jointcal::ConstrainedFluxModel, lsst::jointcal::ConstrainedMagnitudeModel, lsst::jointcal::SimpleFluxModel, and lsst::jointcal::SimpleMagnitudeModel.

transform()

virtual double lsst::jointcal::PhotometryModel::transform ( CcdImage const & ccdImage, MeasuredStar const & measuredStar ) const

pure virtual

Return the on-sky transformed flux for measuredStar on ccdImage.

Parameters

[in]	ccdImage	The ccdImage where measuredStar resides.
	measuredStar	The measured star position to transform.

Returns

The on-sky flux transformed from instFlux at measuredStar's position.

Implemented in lsst::jointcal::ConstrainedFluxModel, lsst::jointcal::ConstrainedMagnitudeModel, lsst::jointcal::SimpleFluxModel, and lsst::jointcal::SimpleMagnitudeModel.

transformError()

virtual double lsst::jointcal::PhotometryModel::transformError ( CcdImage const & ccdImage, MeasuredStar const & measuredStar ) const

pure virtual

Return the on-sky transformed flux uncertainty for measuredStar on ccdImage.

Identical to transform() until freezeErrorTransform() is called.

Parameters

[in]	ccdImage	The ccdImage where measuredStar resides.
	measuredStar	The measured star position to transform.

Returns

The on-sky flux transformed from instFlux at measuredStar's position.

Implemented in lsst::jointcal::ConstrainedFluxModel, lsst::jointcal::ConstrainedMagnitudeModel, lsst::jointcal::SimpleFluxModel, and lsst::jointcal::SimpleMagnitudeModel.

tweakFluxError()

double lsst::jointcal::PhotometryModel::tweakFluxError ( jointcal::MeasuredStar const & measuredStar ) const

inline

Add a fraction of the instrumental flux to the instrumental flux error, in quadrature.

Definition at line 200 of file PhotometryModel.h.

                                                                          {
        if (errorPedestal == 0) {
            return measuredStar.getInstFluxErr();
        } else {
            return std::hypot(measuredStar.getInstFluxErr(), measuredStar.getInstFlux() * errorPedestal);
        }
    }

tweakMagnitudeError()

double lsst::jointcal::PhotometryModel::tweakMagnitudeError ( jointcal::MeasuredStar const & measuredStar ) const

inline

Add a small magnitude offset to the "instrumental magnitude" error, in quadrature.

Definition at line 209 of file PhotometryModel.h.

                                                                               {
        if (errorPedestal == 0) {
            return measuredStar.getInstMagErr();
        } else {
            return std::hypot(measuredStar.getInstMagErr(), errorPedestal);
        }
    }

validate()

bool lsst::jointcal::PhotometryModel::validate	(	CcdImageList const &	ccdImageList,
		int	ndof ) const

Return true if this is a "reasonable" model.

A valid photometry model is positive within each sensor's bounding box.

Parameters

ccdImageList	The ccdImages to test the model validity on.
ndof	The number of degrees of freedom in the fit, e.g. from Fitterbase.computeChi2().

Returns

True if the model is valid on all ccdImages.

Definition at line 33 of file PhotometryModel.cc.

                                                                               {
    bool check = true;
    for (auto const &ccdImage : ccdImageList) {
        // Don't short circuit so that we log every place the model is negative.
        check &= checkPositiveOnBBox(*ccdImage);
    }
    if (ndof < 0) {
        check &= false;
        LOGLS_ERROR(_log, "This model only has "
                                  << ndof << " degrees of freedom, with " << getTotalParameters()
                                  << " total parameters. Reduce the model complexity (e.g. polynomial order)"
                                     " to better match the number of measured sources.");
    }
    return check;
}

Friends And Related Symbol Documentation

operator<<

std::ostream & operator<< ( std::ostream & s, PhotometryModel const & model )

friend

Definition at line 192 of file PhotometryModel.h.

                                                                               {
        model.print(s);
        return s;
    }

Member Data Documentation

_log

LOG_LOGGER lsst::jointcal::PhotometryModel::_log

protected

lsst.logging instance, to be created by a subclass so that messages have consistent name.

Definition at line 224 of file PhotometryModel.h.

errorPedestal

double lsst::jointcal::PhotometryModel::errorPedestal

protected

Definition at line 227 of file PhotometryModel.h.

---

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/jointcal/gbb8dafda3b+f991a0b59f/include/lsst/jointcal/PhotometryModel.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/jointcal/gbb8dafda3b+f991a0b59f/src/PhotometryModel.cc