Class UnitTransformedLikelihood

Inheritance Relationships

Base Type

Class Documentation

class UnitTransformedLikelihood : public lsst::meas::modelfit::Likelihood

A concrete Likelihood class that does not require its parameters and data to be in the same UnitSystem.

This is the main concrete Likelihood class using when fitting sources, even in the case where the measurement UnitSystem is the same as that of the data; we always prefer to fit in a special UnitSystem (see modelfitUnits), using this class to transform the model realization when comparing to the data. This makes forced photometry and modelfit measurements just as easy as single-frame measurements (aside from data access); one can simply initialize a UnitTransformedLikelihood with multiple exposures instead of a single exposure to fit simultaneously to multiple exposures.

Public Functions

void computeModelMatrix(ndarray::Array<Pixel, 2, -1> const &modelMatrix, ndarray::Array<Scalar const, 1, 1> const &nonlinear, bool doApplyWeights = true) const

Evaluate the model for the given vector of nonlinear parameters.

Parameters

  • [out] modelMatrix: The dataDim x amplitudeDim matrix \(B\) that expresses the model projected in such a way that it can be compared to the data when multiplied by an amplitude vector \(\alpha\). It should be weighted if the data vector is. The caller is responsible for guaranteeing that the shape of the matrix correct, but implementations should not assume anything about the initial values of the matrix elements.

  • [in] nonlinear: Vector of nonlinear parameters at which to evaluate the model.

  • [in] doApplyWeights: If False, do not apply the weights to the modelMatrix.

lsst::meas::modelfit::UnitTransformedLikelihood::UnitTransformedLikelihood(PTR ( Model ) model, ndarray::Array< Scalar const, 1, 1 > const & fixed, UnitSystem const & fitSys, geom::SpherePoint const & position, std::vector< PTR ( EpochFootprint )> const & epochFootprintList, UnitTransformedLikelihoodControl const & ctrl)

Initialize a UnitTransformedLikelihood with data from multiple exposures.

Parameters

  • [in] model: Object that defines the model to fit and its parameters.

  • [in] fixed: Model parameters that are held fixed.

  • [in] fitSys: Geometric and photometric system to fit in

  • [in] position: ICRS sky position of object being fit

  • [in] epochFootprintList: List of shared pointers to EpochFootprint

  • [in] ctrl: Control object with various options

lsst::meas::modelfit::UnitTransformedLikelihood::UnitTransformedLikelihood(PTR ( Model ) model, ndarray::Array< Scalar const, 1, 1 > const & fixed, UnitSystem const & fitSys, geom::SpherePoint const & position, afw::image::Exposure < Pixel > const & exposure, afw::detection::Footprint const & footprint, shapelet::MultiShapeletFunction const & psf, UnitTransformedLikelihoodControl const & ctrl)

Initialize a UnitTransformedLikelihood with data from multiple exposures.

Parameters

  • [in] model: Object that defines the model to fit and its parameters.

  • [in] fixed: Model parameters that are held fixed.

  • [in] fitSys: Geometric and photometric system to fit in

  • [in] position: ICRS sky position of object being fit

  • [in] exposure: Exposure containing the data to fit

  • [in] footprint: Footprint that defines the pixels to include in the fit

  • [in] psf: Shapelet approximation to the PSF

  • [in] ctrl: Control object with various options

virtual ~UnitTransformedLikelihood()