Base class for algorithms that measure the properties of sources on one image, using previous measurements on another image to hold certain quantities fixed. More...

#include <Algorithm.h>

Inheritance diagram for lsst::meas::base::ForcedAlgorithm:

Public Member Functions
virtual void	measureForced (afw::table::SourceRecord &measRecord, afw::image::Exposure< float > const &exposure, afw::table::SourceRecord const &refRecord, afw::geom::SkyWcs const &refWcs) const =0
	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	fail (afw::table::SourceRecord &measRecord, MeasurementError *error=nullptr) const =0
	Handle an exception thrown by the current algorithm by setting flags in the given record. More...

std::string	getLogName () const

Protected Attributes
std::string	_logName

Detailed Description

Base class for algorithms that measure the properties of sources on one image, using previous measurements on another image to hold certain quantities fixed.

ForcedAlgorithm can be used when measuring both on single exposures and coadds, and is typically used to measure colors by holding centroids, apertures, or other model parameters fixed while allowing amplitudes to vary.

In addition to the virtual methods defined here, ForcedAlgorithm also puts requirements on constructor signatures; see the wrapForcedAlgorithm Python function for more information.

Most algorithms will not need to make use of the reference record or WCS, as transformed centroids and shapes should generally be available via the slots in measRecord, but these are made available for algorithms that need to transform more complex information. If that is the case, the algorithm may want to inherit from SimpleAlgorithm instead of inheriting from ForcedAlgorithm directly.

Definition at line 127 of file Algorithm.h.

Member Function Documentation

◆ fail()

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

pure virtualinherited

Handle an exception thrown by the current algorithm by setting flags in the given record.

fail() is called by the measurement framework when an exception is allowed to propagate out of one the algorithm's measure() methods. It should generally set both a general failure flag for the algorithm as well as a specific flag indicating the error condition, if possible. To aid in this, if the exception was an instance of MeasurementError, it will be passed in, carrying information about what flag to set.

An algorithm can also to chose to set flags within its own measure() methods, and then just return, rather than throw an exception. However, fail() should be implemented even when all known failure modes do not throw exceptions, to ensure that unexpected exceptions thrown in lower-level code are properly handled.

◆ 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

◆ measureForced()

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

pure virtual

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.

Implemented in lsst::meas::extensions::photometryKron::KronFluxAlgorithm, and lsst::meas::base::SimpleAlgorithm.

◆ measureNForced()

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

virtual

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 in lsst::meas::base::SimpleAlgorithm.

Definition at line 36 of file Algorithm.cc.

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

Member Data Documentation

◆ _logName

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

protectedinherited

Definition at line 69 of file Algorithm.h.

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

/j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/meas_base/22.0.1-25-gb120d7b+8b5510f75f/include/lsst/meas/base/Algorithm.h
/j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/meas_base/22.0.1-25-gb120d7b+8b5510f75f/src/Algorithm.cc

Public Member Functions

Protected Attributes