lsst.meas.astrom.directMatch.DirectMatchTask Class Reference

Inheritance diagram for lsst.meas.astrom.directMatch.DirectMatchTask:

Public Member Functions
def	__init__ (self, butler=None, refObjLoader=None, **kwargs)
def	setRefObjLoader (self, refObjLoader)
def	run (self, catalog, filterName=None, epoch=None)
def	calculateCircle (self, catalog)

Public Attributes
	refObjLoader

Static Public Attributes
	ConfigClass = DirectMatchConfig

Detailed Description

Simple, brute force matching of a source catalog to a reference catalog.

Parameters
----------
butler : `lsst.daf.persistence.Butler`
    Data butler containing the relevant reference catalog data.
refObjLoader : `lsst.meas.algorithms.LoadReferenceObjectsTask` or `None`
    For loading reference objects.
**kwargs
    Other keyword arguments required for instantiating a Task (such as
    ``config``).

Definition at line 29 of file directMatch.py.

Constructor & Destructor Documentation

__init__()

def lsst.meas.astrom.directMatch.DirectMatchTask.__init__	(		self,
			butler = None,
			refObjLoader = None,
		**	kwargs
	)

Definition at line 45 of file directMatch.py.

    def __init__(self, butler=None, refObjLoader=None, **kwargs):
        Task.__init__(self, **kwargs)
        if not refObjLoader:
            if butler:
                if not isinstance(self.config, DirectMatchConfig):
                    raise RuntimeError("DirectMatchTask must be initialized with DirectMatchConfig "
                                       "if a refObjLoader is not supplied at initialization")
                self.makeSubtask("refObjLoader", butler=butler)
            else:
                self.refObjLoader = None
 
        else:
            self.refObjLoader = refObjLoader
        self.makeSubtask("sourceSelection")
        self.makeSubtask("referenceSelection")
 

Member Function Documentation

calculateCircle()

def lsst.meas.astrom.directMatch.DirectMatchTask.calculateCircle	(		self,
			catalog
	)

Calculate a circle enclosing the catalog.

Parameters
----------
catalog : `lsst.afw.table.SourceCatalog`
    Catalog to encircle.

Returns
-------
result : `lsst.pipe.base.Struct`
    Result struct with components:

    ``center``
        ICRS center coordinate (`lsst.afw.geom.SpherePoint`).
    ``radius``
        Radius of the circle (`lsst.geom.Angle`).

Definition at line 123 of file directMatch.py.

    def calculateCircle(self, catalog):
        """Calculate a circle enclosing the catalog.
 
        Parameters
        ----------
        catalog : `lsst.afw.table.SourceCatalog`
            Catalog to encircle.
 
        Returns
        -------
        result : `lsst.pipe.base.Struct`
            Result struct with components:
 
            ``center``
                ICRS center coordinate (`lsst.afw.geom.SpherePoint`).
            ``radius``
                Radius of the circle (`lsst.geom.Angle`).
        """
        coordList = [src.getCoord() for src in catalog]
        center = averageSpherePoint(coordList)
        radius = max(center.separation(coord) for coord in coordList)
        return Struct(center=center, radius=radius + self.config.matchRadius*arcseconds)

run()

def lsst.meas.astrom.directMatch.DirectMatchTask.run	(		self,
			catalog,
			filterName = None,
			epoch = None
	)

Load reference objects and match to them.

Parameters
----------
catalog : `lsst.afw.table.SourceCatalog`
    Catalog to match.
filterName : `str`
    Name of filter loading fluxes.
epoch : `astropy.time.Time` or `None`
    Epoch to which to correct proper motion and parallax, or `None` to
    not apply such corrections.

Returns
-------
result : `lsst.pipe.base.Struct`
    Result struct with components:

    ``matches``
        Matched sources with associated reference
        (`lsst.afw.table.SourceMatchVector`).
    ``matchMeta``
        Match metadata (`lsst.meas.astrom.MatchMetadata`).

Definition at line 76 of file directMatch.py.

    def run(self, catalog, filterName=None, epoch=None):
        """Load reference objects and match to them.
 
        Parameters
        ----------
        catalog : `lsst.afw.table.SourceCatalog`
            Catalog to match.
        filterName : `str`
            Name of filter loading fluxes.
        epoch : `astropy.time.Time` or `None`
            Epoch to which to correct proper motion and parallax, or `None` to
            not apply such corrections.
 
        Returns
        -------
        result : `lsst.pipe.base.Struct`
            Result struct with components:
 
            ``matches``
                Matched sources with associated reference
                (`lsst.afw.table.SourceMatchVector`).
            ``matchMeta``
                Match metadata (`lsst.meas.astrom.MatchMetadata`).
        """
        if self.refObjLoader is None:
            raise RuntimeError("Running matcher task with no refObjLoader set in __ini__ or setRefObjLoader")
        circle = self.calculateCircle(catalog)
        matchMeta = self.refObjLoader.getMetadataCircle(circle.center, circle.radius, filterName, epoch=epoch)
        emptyResult = Struct(matches=[], matchMeta=matchMeta)
        sourceSelection = self.sourceSelection.run(catalog)
        if len(sourceSelection.sourceCat) == 0:
            self.log.warning("No objects selected from %d objects in source catalog", len(catalog))
            return emptyResult
        refData = self.refObjLoader.loadSkyCircle(circle.center, circle.radius, filterName, epoch=epoch)
        refCat = refData.refCat
        refSelection = self.referenceSelection.run(refCat)
        if len(refSelection.sourceCat) == 0:
            self.log.warning("No objects selected from %d objects in reference catalog", len(refCat))
            return emptyResult
        matches = afwTable.matchRaDec(refSelection.sourceCat, sourceSelection.sourceCat,
                                      self.config.matchRadius*arcseconds)
        self.log.info("Matched %d from %d/%d input and %d/%d reference sources",
                      len(matches), len(sourceSelection.sourceCat), len(catalog),
                      len(refSelection.sourceCat), len(refCat))
        return Struct(matches=matches, matchMeta=matchMeta, refCat=refCat, sourceSelection=sourceSelection,
                      refSelection=refSelection)
 

setRefObjLoader()

def lsst.meas.astrom.directMatch.DirectMatchTask.setRefObjLoader	(		self,
			refObjLoader
	)

Set the reference object loader for the task.

Parameters
----------
refObjLoader
    An instance of a reference object loader, either a
    `lsst.meas.algorithms.LoadReferenceObjectsTask` task or a
    `lsst.meas.algorithms.ReferenceObjectLoader` instance. A task can
    be used as a subtask and is generally used in gen2 middleware. The
    class is designed to be used with gen3 middleware and is
    initialized outside the normal task framework.

Definition at line 61 of file directMatch.py.

    def setRefObjLoader(self, refObjLoader):
        """Set the reference object loader for the task.
 
        Parameters
        ----------
        refObjLoader
            An instance of a reference object loader, either a
            `lsst.meas.algorithms.LoadReferenceObjectsTask` task or a
            `lsst.meas.algorithms.ReferenceObjectLoader` instance. A task can
            be used as a subtask and is generally used in gen2 middleware. The
            class is designed to be used with gen3 middleware and is
            initialized outside the normal task framework.
        """
        self.refObjLoader = refObjLoader
 

Member Data Documentation

ConfigClass

lsst.meas.astrom.directMatch.DirectMatchTask.ConfigClass = DirectMatchConfig

static

Definition at line 42 of file directMatch.py.

refObjLoader

lsst.meas.astrom.directMatch.DirectMatchTask.refObjLoader

Definition at line 54 of file directMatch.py.

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/meas_astrom/22.0.1-12-g44dc1dc+2a20fdde0d/python/lsst/meas/astrom/directMatch.py