lsst.pipe.tasks.mocks.mockObject.MockObjectTask Class Reference

Inheritance diagram for lsst.pipe.tasks.mocks.mockObject.MockObjectTask:

Public Member Functions
def	__init__ (self, **kwds)
def	run (self, tractInfo, catalog=None)
def	makePositions (self, tractInfo)
def	defineObject (self, record)
def	drawSource (self, record, exposure, buffer=0)

Public Attributes
	schema
	center
	magKey
	rng

Static Public Attributes
	ConfigClass = MockObjectConfig

Detailed Description

Task that generates simple mock objects and draws them on images, intended as a subtask of
MockCoaddTask.

May be subclassed to generate things other than stars.

Definition at line 46 of file mockObject.py.

Constructor & Destructor Documentation

__init__()

def lsst.pipe.tasks.mocks.mockObject.MockObjectTask.__init__	(		self,
		**	kwds
	)

Definition at line 55 of file mockObject.py.

    def __init__(self, **kwds):
        lsst.pipe.base.Task.__init__(self, **kwds)
        self.schema = lsst.afw.table.SimpleTable.makeMinimalSchema()
        self.center = lsst.afw.table.Point2DKey.addFields(self.schema, "center",
                                                          "center position in tract WCS", "pixel")
        self.magKey = self.schema.addField("mag", type=float, doc="exact true magnitude")
        self.rng = numpy.random.RandomState(self.config.seed)
 

Member Function Documentation

defineObject()

def lsst.pipe.tasks.mocks.mockObject.MockObjectTask.defineObject	(		self,
			record
	)

Fill in additional fields in a truth catalog record (id and coord will already have
been set).

Definition at line 101 of file mockObject.py.

    def defineObject(self, record):
        """Fill in additional fields in a truth catalog record (id and coord will already have
        been set).
        """
        mag = self.rng.rand() * (self.config.maxMag - self.config.minMag) + self.config.minMag
        record.setD(self.magKey, mag)
 

drawSource()

def lsst.pipe.tasks.mocks.mockObject.MockObjectTask.drawSource	(		self,
			record,
			exposure,
			buffer = 0
	)

Draw the given truth catalog record on the given exposure, makings use of its Psf, Wcs,
PhotoCalib, and possibly filter to transform it appropriately.

The mask and variance planes of the Exposure are ignored.

The 'buffer' parameter is used to expand the source's bounding box when testing whether it
is considered fully part of the image.

Returns 0 if the object does not appear on the given image at all, 1 if it appears partially,
and 2 if it appears fully (including the given buffer).

Definition at line 108 of file mockObject.py.

    def drawSource(self, record, exposure, buffer=0):
        """Draw the given truth catalog record on the given exposure, makings use of its Psf, Wcs,
        PhotoCalib, and possibly filter to transform it appropriately.
 
        The mask and variance planes of the Exposure are ignored.
 
        The 'buffer' parameter is used to expand the source's bounding box when testing whether it
        is considered fully part of the image.
 
        Returns 0 if the object does not appear on the given image at all, 1 if it appears partially,
        and 2 if it appears fully (including the given buffer).
        """
        wcs = exposure.getWcs()
        center = wcs.skyToPixel(record.getCoord())
        try:
            psfImage = exposure.getPsf().computeImage(center).convertF()
        except Exception:
            return 0
        psfBBox = psfImage.getBBox()
        overlap = exposure.getBBox()
        overlap.clip(psfBBox)
        if overlap.isEmpty():
            return 0
        flux = exposure.getPhotoCalib().magnitudeToInstFlux(record.getD(self.magKey))
        normalization = flux / psfImage.getArray().sum()
        if psfBBox != overlap:
            psfImage = psfImage.Factory(psfImage, overlap)
            result = 1
        else:
            result = 2
            if buffer != 0:
                bufferedBBox = lsst.geom.Box2I(psfBBox)
                bufferedBBox.grow(buffer)
                bufferedOverlap = exposure.getBBox()
                bufferedOverlap.clip(bufferedBBox)
                if bufferedOverlap != bufferedBBox:
                    result = 1
        image = exposure.getMaskedImage().getImage()
        subImage = image.Factory(image, overlap)
        subImage.scaledPlus(normalization, psfImage)
        return result

makePositions()

def lsst.pipe.tasks.mocks.mockObject.MockObjectTask.makePositions	(		self,
			tractInfo
	)

Generate the centers (as a (coord, point) tuple) of mock objects (the point returned is
in the tract coordinate system).

Default implementation puts objects on a grid that is square in the tract's image coordinate
system, with spacing approximately given by config.spacings.

The return value is a Python iterable over (coord, point) pairs; the default implementation
is actually an iterator (i.e. the function is a "generator"), but derived-class overrides may
return any iterable.

Definition at line 83 of file mockObject.py.

    def makePositions(self, tractInfo):
        """Generate the centers (as a (coord, point) tuple) of mock objects (the point returned is
        in the tract coordinate system).
 
        Default implementation puts objects on a grid that is square in the tract's image coordinate
        system, with spacing approximately given by config.spacings.
 
        The return value is a Python iterable over (coord, point) pairs; the default implementation
        is actually an iterator (i.e. the function is a "generator"), but derived-class overrides may
        return any iterable.
        """
        wcs = tractInfo.getWcs()
        spacing = self.config.spacing / wcs.getPixelScale().asArcseconds()  # get spacing in tract pixels
        bbox = tractInfo.getBBox()
        for y in numpy.arange(bbox.getMinY() + 0.5 * spacing, bbox.getMaxY(), spacing):
            for x in numpy.arange(bbox.getMinX() + 0.5 * spacing, bbox.getMaxX(), spacing):
                yield wcs.pixelToSky(x, y), lsst.geom.Point2D(x, y),
 

run()

def lsst.pipe.tasks.mocks.mockObject.MockObjectTask.run	(		self,
			tractInfo,
			catalog = None
	)

Add records to the truth catalog and return it, delegating to makePositions and defineObject.

If the given catalog is not None, add records to this catalog and return it instead
of creating a new one.

Subclasses should generally not need to override this method.

Definition at line 63 of file mockObject.py.

    def run(self, tractInfo, catalog=None):
        """Add records to the truth catalog and return it, delegating to makePositions and defineObject.
 
        If the given catalog is not None, add records to this catalog and return it instead
        of creating a new one.
 
        Subclasses should generally not need to override this method.
        """
        if catalog is None:
            catalog = lsst.afw.table.SimpleCatalog(self.schema)
        else:
            if not catalog.getSchema().contains(self.schema):
                raise ValueError("Catalog schema does not match Task schema")
        for coord, center in self.makePositions(tractInfo):
            record = catalog.addNew()
            record.setCoord(coord)
            record.set(self.center, center)
            self.defineObject(record)
        return catalog
 

Member Data Documentation

center

lsst.pipe.tasks.mocks.mockObject.MockObjectTask.center

Definition at line 58 of file mockObject.py.

ConfigClass

lsst.pipe.tasks.mocks.mockObject.MockObjectTask.ConfigClass = MockObjectConfig

static

Definition at line 53 of file mockObject.py.

magKey

lsst.pipe.tasks.mocks.mockObject.MockObjectTask.magKey

Definition at line 60 of file mockObject.py.

rng

lsst.pipe.tasks.mocks.mockObject.MockObjectTask.rng

Definition at line 61 of file mockObject.py.

schema

lsst.pipe.tasks.mocks.mockObject.MockObjectTask.schema

Definition at line 57 of file mockObject.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/pipe_tasks/21.0.0-172-gfb10e10a+18fedfabac/python/lsst/pipe/tasks/mocks/mockObject.py