coaddInputRecorder.py

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#!/usr/bin/env python
#
# LSST Data Management System
# Copyright 2008, 2009, 2010, 2011, 2012 LSST Corporation.
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import numpy

import lsst.pex.config as pexConfig
import lsst.afw.table as afwTable
import lsst.afw.image as afwImage
import lsst.pipe.base as pipeBase
from lsst.meas.algorithms import CoaddPsf, makeCoaddApCorrMap

__all__ = ["CoaddInputRecorderTask"]

class CoaddInputRecorderConfig(pexConfig.Config):
    """Config for CoaddInputRecorderTask

    The inputRecorder section of the various coadd tasks' configs should generally agree,
    or the schemas created by earlier tasks (like MakeCoaddTempExpTask) will not contain
    the fields filled by later tasks (like AssembleCoaddTask).
    """
    saveEmptyCcds = pexConfig.Field(
        dtype=bool, default=False, optional=False,
        doc=("Add records for CCDs we iterated over but did not add a coaddTempExp"
             " due to a lack of unmasked pixels in the coadd footprint.")
    )
    saveErrorCcds = pexConfig.Field(
        dtype=bool, default=False, optional=False,
        doc=("Add records for CCDs we iterated over but did not add a coaddTempExp"
             " due to an exception (often due to the calexp not being found on disk).")
    )
    saveVisitGoodPix = pexConfig.Field(
        dtype=bool, default=True, optional=False,
        doc=("Save the total number of good pixels in each coaddTempExp (redundant with a sum of"
             " good pixels in associated CCDs)")
    )
    saveCcdWeights = pexConfig.Field(
        dtype=bool, default=True, optional=False,
        doc=("Save weights in the CCDs table as well as the visits table?"
             " (This is necessary for easy construction of CoaddPsf, but otherwise duplicate information.)")
    )

class CoaddTempExpInputRecorder(object):
    """A helper class for CoaddInputRecorderTask, managing the CoaddInputs object for that a single
    CoaddTempExp.  This will contain single 'visit' record for the CoaddTempExp and a number of 'ccd'
    records.

    Should generally be created by calling CoaddInputRecorderTask.makeCoaddTempExp().
    """

    def __init__(self, task, visitId):
        self.task = task
        self.coaddInputs = self.task.makeCoaddInputs()
        self.visitRecord = self.coaddInputs.visits.addNew()
        self.visitRecord.setId(visitId)

    def addCalExp(self, calExp, ccdId, nGoodPix):
        """Add a 'ccd' record for a calexp just added to the CoaddTempExp

        @param[in] calExp   Calibrated exposure just added to the CoaddTempExp, or None in case of
                            failures that should nonetheless be tracked.  Should be the original
                            calexp, in that it should contain the original Psf and Wcs, not the
                            warped and/or matched ones.
        @param[in] ccdId    A unique numeric ID for the Exposure.
        @param[in] nGoodPix Number of good pixels this image will contribute to the CoaddTempExp.
                            If saveEmptyCcds is not set and this value is zero, no record will be
                            added.
        """
        if nGoodPix == 0 and not self.task.config.saveEmptyCcds:
            return
        record = self.coaddInputs.ccds.addNew()
        record.setId(ccdId)
        record.setL(self.task.ccdVisitKey, self.visitRecord.getId())
        try:
            record.setI(self.task.ccdCcdKey, calExp.getDetector().getId())
        except:
            self.task.log.warn("Error getting detector serial number in visit %d; using -1"
                                   % self.visitRecord.getId())
            record.setI(self.task.ccdCcdKey, -1)
        record.setI(self.task.ccdGoodPixKey, nGoodPix)
        if calExp is not None:
            record.setPsf(calExp.getPsf())
            record.setWcs(calExp.getWcs())
            record.setBBox(calExp.getBBox())
            record.setApCorrMap(calExp.getInfo().getApCorrMap())
            record.setValidPolygon(calExp.getInfo().getValidPolygon())
            if self.task.config.saveCcdWeights:
                record.setD(self.task.ccdWeightKey, 1.0) # No weighting or overlap when warping

    def finish(self, coaddTempExp, nGoodPix=None):
        """Finish creating the CoaddInputs for a CoaddTempExp.

        @param[in,out] coaddTempExp   Exposure object from which to obtain the PSF, WCS, and bounding
                                      box for the entry in the 'visits' table.  On return, the completed
                                      CoaddInputs object will be attached to it.
        @param[in]     nGoodPix       Total number of good pixels in the CoaddTempExp; ignored unless
                                      saveVisitGoodPix is true.
        """
        self.visitRecord.setPsf(coaddTempExp.getPsf())
        self.visitRecord.setWcs(coaddTempExp.getWcs())
        self.visitRecord.setValidPolygon(coaddTempExp.getInfo().getValidPolygon())
        self.visitRecord.setBBox(coaddTempExp.getBBox())
        if self.task.config.saveVisitGoodPix:
            self.visitRecord.setI(self.task.visitGoodPixKey, nGoodPix)
        coaddTempExp.getInfo().setCoaddInputs(self.coaddInputs)
        wcs = coaddTempExp.getWcs()
        if False:
            # This causes a test failure, pending fix in issue HSC-802
            coaddTempExp.setPsf(CoaddPsf(self.coaddInputs.ccds, wcs))
        apCorrMap = makeCoaddApCorrMap(self.coaddInputs.ccds, coaddTempExp.getBBox(afwImage.PARENT), wcs)
        coaddTempExp.getInfo().setApCorrMap(apCorrMap)

class CoaddInputRecorderTask(pipeBase.Task):
    """Subtask that handles filling a CoaddInputs object for a coadd exposure, tracking the CCDs and
    visits that went into a coadd.

    The interface here is a little messy, but I think this is at least partly a product of a bit of
    messiness in the coadd code it's plugged into.  I hope #2590 might result in a better design.
    """

    ConfigClass = CoaddInputRecorderConfig

    def __init__(self, *args, **kwargs):
        pipeBase.Task.__init__(self, *args, **kwargs)        
        self.visitSchema = afwTable.ExposureTable.makeMinimalSchema()
        if self.config.saveVisitGoodPix:
            self.visitGoodPixKey = self.visitSchema.addField("goodpix", type=int,
                                                             doc="Number of good pixels in the coaddTempExp")
        self.visitWeightKey = self.visitSchema.addField("weight", type=float,
                                                        doc="Weight for this visit in the coadd")
        self.ccdSchema = afwTable.ExposureTable.makeMinimalSchema()
        self.ccdCcdKey = self.ccdSchema.addField("ccd", type=int, doc="cameraGeom CCD serial number")
        self.ccdVisitKey = self.ccdSchema.addField("visit", type=numpy.int64,
                                                   doc="Foreign key for the visits (coaddTempExp) catalog")
        self.ccdGoodPixKey = self.ccdSchema.addField("goodpix", type=int,
                                                     doc="Number of good pixels in this CCD")
        if self.config.saveCcdWeights:
            self.ccdWeightKey = self.ccdSchema.addField("weight", type=float,
                                                        doc="Weight for this visit in the coadd")

    def makeCoaddTempExpRecorder(self, visitId):
        """Return a CoaddTempExpInputRecorder instance to help with saving a CoaddTempExp's inputs.

        The visitId may be any number that is unique for each CoaddTempExp that goes into a coadd,
        but ideally should be something more meaningful that can be used to reconstruct a data ID.
        """
        return CoaddTempExpInputRecorder(self, visitId)

    def makeCoaddInputs(self):
        """Create a CoaddInputs object with schemas defined by the task configuration"""
        return afwImage.CoaddInputs(self.visitSchema, self.ccdSchema)

    def addVisitToCoadd(self, coaddInputs, coaddTempExp, weight):
        """Called by AssembleCoaddTask when adding (a subset of) a coaddTempExp to a coadd.  The
        base class impementation extracts the CoaddInputs from the coaddTempExp and appends
        them to the given coaddInputs, filling in the weight column(s).

        Note that the passed coaddTempExp may be a subimage, but that this method will only be
        called for the first subimage

        Returns the record for the visit to allow subclasses to fill in additional fields.
        Warns and returns None if the inputRecorder catalogs for the coaddTempExp are not usable.
        """
        tempExpInputs = coaddTempExp.getInfo().getCoaddInputs()
        if len(tempExpInputs.visits) != 1:
            self.log.warn("CoaddInputs for coaddTempExp should have exactly one record in visits table "
                          "(found %d).  CoaddInputs for this visit will not be saved."
                          % len(tempExpInputs.visits))
            return None
        inputVisitRecord = tempExpInputs.visits[0];
        outputVisitRecord = coaddInputs.visits.addNew()
        outputVisitRecord.assign(inputVisitRecord)
        outputVisitRecord.setD(self.visitWeightKey, weight)
        for inputCcdRecord in tempExpInputs.ccds:
            if inputCcdRecord.getL(self.ccdVisitKey) != inputVisitRecord.getId():
                self.log.warn("CoaddInputs for coaddTempExp with id %d contains CCDs with visit=%d. "
                              "CoaddInputs may be unreliable."
                              % (inputVisitRecord.getId(), inputCcdRecord.getL(self.ccdVisitKey)))
            outputCcdRecord = coaddInputs.ccds.addNew()
            outputCcdRecord.assign(inputCcdRecord)
            if self.config.saveCcdWeights:
                outputCcdRecord.setD(self.ccdWeightKey, weight)
        return inputVisitRecord