lsst::meas::algorithms::evalChi2Visitor< PixelT > Class Template Reference

A class to pass around to all our PsfCandidates to evaluate the PSF fit's X^2. More...

Inheritance diagram for lsst::meas::algorithms::evalChi2Visitor< PixelT >:

Public Member Functions
	evalChi2Visitor (afw::math::Kernel const &kernel, double lambda)
void	reset ()
void	processCandidate (afw::math::SpatialCellCandidate *candidate)
double	getValue () const

Detailed Description

template<typename PixelT>
class lsst::meas::algorithms::evalChi2Visitor< PixelT >

A class to pass around to all our PsfCandidates to evaluate the PSF fit's X^2.

Definition at line 431 of file SpatialModelPsf.cc.

Constructor & Destructor Documentation

evalChi2Visitor()

template<typename PixelT >

lsst::meas::algorithms::evalChi2Visitor< PixelT >::evalChi2Visitor ( afw::math::Kernel const &  kernel, double  lambda  )

inlineexplicit

Definition at line 439 of file SpatialModelPsf.cc.

            : afw::math::CandidateVisitor(),
              _chi2(0.0),
              _kernel(kernel),
              _lambda(lambda),
              _kImage(std::shared_ptr<KImage>(new KImage(kernel.getDimensions()))) {}

Member Function Documentation

getValue()

template<typename PixelT >

double lsst::meas::algorithms::evalChi2Visitor< PixelT >::getValue ( ) const

inline

Definition at line 486 of file SpatialModelPsf.cc.

{ return _chi2; }

processCandidate()

template<typename PixelT >

void lsst::meas::algorithms::evalChi2Visitor< PixelT >::processCandidate ( afw::math::SpatialCellCandidate *  candidate )

inlinevirtual

Reimplemented from lsst::afw::math::CandidateVisitor.

Definition at line 449 of file SpatialModelPsf.cc.

                                                                  {
        PsfCandidate<PixelT>* imCandidate = dynamic_cast<PsfCandidate<PixelT>*>(candidate);
        if (imCandidate == NULL) {
            throw LSST_EXCEPT(lsst::pex::exceptions::LogicError,
                              "Failed to cast SpatialCellCandidate to PsfCandidate");
        }
 
        double const xcen = imCandidate->getSource()->getX();
        double const ycen = imCandidate->getSource()->getY();
 
        _kernel.computeImage(*_kImage, true, xcen, ycen);
        std::shared_ptr<MaskedImage const> data;
        try {
            data = imCandidate->getOffsetImage(WARP_ALGORITHM, WARP_BUFFER);
        } catch (lsst::pex::exceptions::LengthError&) {
            return;
        }
 
        try {
            std::pair<double, double> result =
                    fitKernel(*_kImage, *data, _lambda, false, imCandidate->getSource()->getId());
 
            double dchi2 = result.first;       // chi^2 from this object
            double const amp = result.second;  // estimate of amplitude of model at this point
 
            imCandidate->setChi2(dchi2);
            imCandidate->setAmplitude(amp);
 
            _chi2 += dchi2;
        } catch (lsst::pex::exceptions::RangeError& e) {
            imCandidate->setStatus(afw::math::SpatialCellCandidate::BAD);
            imCandidate->setChi2(std::numeric_limits<double>::quiet_NaN());
            imCandidate->setAmplitude(std::numeric_limits<double>::quiet_NaN());
        }
    }

reset()

template<typename PixelT >

void lsst::meas::algorithms::evalChi2Visitor< PixelT >::reset ( )

inlinevirtual

Reimplemented from lsst::afw::math::CandidateVisitor.

Definition at line 446 of file SpatialModelPsf.cc.

{ _chi2 = 0.0; }

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-4.0.1/Linux64/meas_algorithms/gc655b1545f+ade567573c/src/SpatialModelPsf.cc