LSSTApplications: lsst.meas.base.applyApCorr.ApplyApCorrTask Class Reference

Apply aperture corrections. More...

Inheritance diagram for lsst.meas.base.applyApCorr.ApplyApCorrTask:

Public Member Functions
def	__init__

def	run

Public Attributes
	apCorrInfoDict

Static Public Attributes
	ConfigClass = ApplyApCorrConfig

Static Private Attributes
string	_DefaultName = "applyApCorr"

Detailed Description

Apply aperture corrections.

Definition at line 106 of file applyApCorr.py.

Constructor & Destructor Documentation

def lsst.meas.base.applyApCorr.ApplyApCorrTask.__init__	(	self,
		schema,
		kwds
	)

Construct an instance of this task

Definition at line 112 of file applyApCorr.py.

 
     def __init__(self, schema, **kwds):
         """Construct an instance of this task
         """
         lsst.pipe.base.Task.__init__(self, **kwds)
 
         self.apCorrInfoDict = dict()
         apCorrNameSet = getApCorrNameSet()
         ignoreSet = set(self.config.ignoreList)
         missingNameSet = ignoreSet - set(apCorrNameSet)
         if missingNameSet:
             self.log.warn("Fields in ignoreList that are not in fluxCorrectList: %s" %
                 (sorted(list(missingNameSet)),))
         for name in apCorrNameSet - ignoreSet:
             if name + "_flux" in schema:
                 self.apCorrInfoDict[name] = ApCorrInfo(schema=schema, name=name)
             else:
                 # if a field in the registry is missing from the schema, silently ignore it.
                 pass

lsst::meas::base.applyApCorr.ApplyApCorrTask.apCorrInfoDict

apCorrInfoDict

Definition: applyApCorr.py:117

lsst::meas::base.applyApCorr.ApplyApCorrTask.__init__

def __init__

Definition: applyApCorr.py:112

lsst::meas::base.apCorrRegistry.getApCorrNameSet

def getApCorrNameSet

Return a copy of the set of field name prefixes for fluxes that should be aperture corrected...

Definition: apCorrRegistry.py:42

lsst::meas::base.applyApCorr.ApCorrInfo

Catalog field names and keys needed to aperture correct a particular flux.

Definition: applyApCorr.py:41

def lsst.meas.base.applyApCorr.ApplyApCorrTask.run	(	self,
		catalog,
		apCorrMap
	)

Apply aperture corrections to a catalog of sources

@param[in,out] catalog  catalog of sources
@param[in] apCorrMap  aperture correction map (an lsst.afw.image.ApCorrMap)

If you show debug-level log messages then you will see statistics for the effects of
aperture correction.

Definition at line 131 of file applyApCorr.py.

 
     def run(self, catalog, apCorrMap):
         """Apply aperture corrections to a catalog of sources
 
         @param[in,out] catalog  catalog of sources
         @param[in] apCorrMap  aperture correction map (an lsst.afw.image.ApCorrMap)
 
         If you show debug-level log messages then you will see statistics for the effects of
         aperture correction.
         """
         self.log.info("Applying aperture corrections to %d flux fields" % (len(self.apCorrInfoDict),))
         if UseNaiveFluxSigma:
             self.log.info("Use naive flux sigma computation")
         else:
             self.log.info("Use complex flux sigma computation that double-counts photon noise "
                 " and thus over-estimates flux uncertainty")
         for apCorrInfo in self.apCorrInfoDict.itervalues():
             apCorrModel = apCorrMap.get(apCorrInfo.fluxName)
             apCorrSigmaModel = apCorrMap.get(apCorrInfo.fluxSigmaName)
             if None in (apCorrModel, apCorrSigmaModel):
                 missingNames = [(apCorrInfo.fluxName, apCorrInfo.fluxSigmaName)[i]
                     for i, model in enumerate((apCorrModel, apCorrSigmaModel)) if model is None]
                 self.log.warn("Could not find %s in apCorrMap" % (" or ".join(missingNames),))
                 for source in catalog:
                     source.set(apCorrInfo.apCorrFlagKey, True)
                 continue
 
             for source in catalog:
                 center = source.getCentroid()
                 # say we've failed when we start; we'll unset these flags when we succeed
                 source.set(apCorrInfo.apCorrFlagKey, True)
                 oldFluxFlagState = False
                 if self.config.doFlagApCorrFailures:
                     oldFluxFlagState = source.get(apCorrInfo.fluxFlagKey)
                     source.set(apCorrInfo.fluxFlagKey, True)
 
                 apCorr = 1.0
                 apCorrSigma = 0.0
                 try:
                     apCorr = apCorrModel.evaluate(center)
                     if not UseNaiveFluxSigma:
                         apCorrSigma = apCorrSigmaModel.evaluate(center)
                 except lsst.pex.exceptions.DomainError:
                     continue
 
                 source.set(apCorrInfo.apCorrKey, apCorr)
                 source.set(apCorrInfo.apCorrSigmaKey, apCorrSigma)
                 if apCorr <= 0.0 or apCorrSigma < 0.0:
                     continue
 
                 flux = source.get(apCorrInfo.fluxKey)
                 fluxSigma = source.get(apCorrInfo.fluxSigmaKey)
                 source.set(apCorrInfo.fluxKey, flux*apCorr)
                 if UseNaiveFluxSigma:
                     source.set(apCorrInfo.fluxSigmaKey, fluxSigma*apCorr)
                 else:
                     a = fluxSigma/flux
                     b = apCorrSigma/apCorr
                     source.set(apCorrInfo.fluxSigmaKey, abs(flux*apCorr)*math.sqrt(a*a + b*b))
                 source.set(apCorrInfo.apCorrFlagKey, False)
                 if self.config.doFlagApCorrFailures:
                     source.set(apCorrInfo.fluxFlagKey, oldFluxFlagState)
 
             if self.log.getThreshold() <= self.log.DEBUG:
                 # log statistics on the effects of aperture correction
                 apCorrArr = numpy.array([s.get(apCorrInfo.apCorrKey) for s in catalog])
                 apCorrSigmaArr = numpy.array([s.get(apCorrInfo.apCorrSigmaKey) for s in catalog])
                 self.log.logdebug("For flux field %r: mean apCorr=%s, stdDev apCorr=%s,"
                     " mean apCorrSigma=%s, stdDev apCorrSigma=%s for %s sources" %
                     (apCorrInfo.name, apCorrArr.mean(), apCorrArr.std(),
                     apCorrSigmaArr.mean(), apCorrSigmaArr.std(), len(catalog)))
 
 

Public Member Functions

Public Attributes

Static Public Attributes

Static Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation