lsst.afw.table.multiMatch.MultiMatch Class Reference

Inheritance diagram for lsst.afw.table.multiMatch.MultiMatch:

Public Member Functions
def	__init__
def	makeRecord
def	add
def	finish

Public Attributes
	radius
	mapper
	coordKey
	idKey
	dataIdKeys
	objectKey
	result
	reference
	ambiguous
	table
	nextObjId

Detailed Description

Definition at line 6 of file multiMatch.py.

Constructor & Destructor Documentation

def lsst.afw.table.multiMatch.MultiMatch.__init__	(		self,
			schema,
			dataIdFormat,
			coordField = "coord",
			idField = "id",
			radius = None,
			RecordClass = SourceRecord
	)

Initialize a multi-catalog match.

Arguments:
  schema -------- schema shared by all catalogs to be included in the match.
  dataIdFormat -- dict of name: type for all data ID keys (e.g. {"visit":int, "ccd":int}).
  coordField ---- prefix for _ra and _dec fields that contain the coordinates to use for the match.
  idField ------- name of the field in schema that contains unique object IDs.
  radius -------- lsst.afw.geom.Angle; maximum separation for a match.  Defaults to 0.5 arcseconds.
  RecordClass --- type of record (a subclass of lsst.afw.table.BaseRecord) to expect in catalogs
          to be matched.

Definition at line 9 of file multiMatch.py.

        RecordClass=SourceRecord):
        """Initialize a multi-catalog match.

        Arguments:
          schema -------- schema shared by all catalogs to be included in the match.
          dataIdFormat -- dict of name: type for all data ID keys (e.g. {"visit":int, "ccd":int}).
          coordField ---- prefix for _ra and _dec fields that contain the coordinates to use for the match.
          idField ------- name of the field in schema that contains unique object IDs.
          radius -------- lsst.afw.geom.Angle; maximum separation for a match.  Defaults to 0.5 arcseconds.
          RecordClass --- type of record (a subclass of lsst.afw.table.BaseRecord) to expect in catalogs
                          to be matched.
        """
        if radius is None:
            radius = 0.5*lsst.afw.geom.arcseconds
        elif not isinstance(radius, lsst.afw.geom.Angle):
            raise ValueError("'radius' argument must be an Angle")
        self.radius = radius
        self.mapper = SchemaMapper(schema)
        self.mapper.addMinimalSchema(schema, True)
        self.coordKey = CoordKey(schema[coordField])
        self.idKey = schema.find(idField).key
        self.dataIdKeys = {}
        outSchema = self.mapper.editOutputSchema()
        self.objectKey = outSchema.addField("object", type=numpy.int64, doc="Unique ID for joined sources")
        for name, dataType in dataIdFormat.iteritems():
            self.dataIdKeys[name] = outSchema.addField(name, type=dataType, doc="'%s' data ID component")
        # self.result will be a catalog containing the union of all matched records, with an 'object' ID
        # column that can be used to group matches.  Sources that have ambiguous matches may appear
        # multiple times.
        self.result = None
        # self.reference will be a subset of self.result, with exactly one record for each group of matches
        # (we'll use the one from the first catalog matched into this group)
        # We'll use this to match against each subsequent catalog.
        self.reference = None
        # A set of ambiguous objects that we may want to ultimately remove from the final merged catalog.
        self.ambiguous = set()
        # Table used to allocate new records for the ouput catalog.
        self.table = RecordClass.Table.make(self.mapper.getOutputSchema())
        # Counter used to assign the next object ID
        self.nextObjId = 1