lsst.pipe.tasks.insertFakes Namespace Reference

Classes
class	InsertFakesConnections

Functions
def	addPixCoords (self, fakeCat, wcs)
def	trimFakeCat (self, fakeCat, image, wcs)
def	mkFakeGalsimGalaxies (self, fakeCat, band, photoCalib, pixelScale, psf, image)
def	mkFakeStars (self, fakeCat, band, photoCalib, psf, image)
def	cleanCat (self, fakeCat, starCheckVal)
def	addFakeSources (self, image, fakeImages, sourceType)

Variables
	correctedFlux = psf.computeApertureFlux(self.config.calibFluxRadius, xy)
	psfKernel = psf.computeKernelImage(xy).getArray()
	psfIm = galsim.InterpolatedImage(galsim.Image(psfKernel), scale=pixelScale)
	galsimIm = galsim.InterpolatedImage(galsim.Image(im.array), scale=pixelScale)
	convIm = galsim.Convolve([galsimIm, psfIm])
	outIm = convIm.drawImage(scale=pixelScale, method="real_space").array
	imSum = np.sum(outIm)
	divIm = outIm/imSum
	flux = photoCalib.magnitudeToInstFlux(mag, xy)
	imWithFlux = flux*divIm

Function Documentation

addFakeSources()

def lsst.pipe.tasks.insertFakes.addFakeSources	(		self,
			image,
			fakeImages,
			sourceType
	)

Add the fake sources to the given image

Parameters
----------
image : `lsst.afw.image.exposure.exposure.ExposureF`
            The image into which the fake sources should be added
fakeImages : `typing.Iterator` [`tuple` ['lsst.afw.image.ImageF`, `lsst.geom.Point2d`]]
            An iterator of tuples that contains (or generates) images of fake sources,
            and the locations they are to be inserted at.
sourceType : `str`
            The type (star/galaxy) of fake sources input

Returns
-------
image : `lsst.afw.image.exposure.exposure.ExposureF`

Notes
-----
Uses the x, y information in the ``fakeCat`` to position an image of the fake interpolated onto the
pixel grid of the image. Sets the ``FAKE`` mask plane for the pixels added with the fake source.

Definition at line 716 of file insertFakes.py.

    def addFakeSources(self, image, fakeImages, sourceType):
        """Add the fake sources to the given image
 
        Parameters
        ----------
        image : `lsst.afw.image.exposure.exposure.ExposureF`
                    The image into which the fake sources should be added
        fakeImages : `typing.Iterator` [`tuple` ['lsst.afw.image.ImageF`, `lsst.geom.Point2d`]]
                    An iterator of tuples that contains (or generates) images of fake sources,
                    and the locations they are to be inserted at.
        sourceType : `str`
                    The type (star/galaxy) of fake sources input
 
        Returns
        -------
        image : `lsst.afw.image.exposure.exposure.ExposureF`
 
        Notes
        -----
        Uses the x, y information in the ``fakeCat`` to position an image of the fake interpolated onto the
        pixel grid of the image. Sets the ``FAKE`` mask plane for the pixels added with the fake source.
        """
 
        imageBBox = image.getBBox()
        imageMI = image.maskedImage
 
        for (fakeImage, xy) in fakeImages:
            X0 = xy.getX() - fakeImage.getWidth()/2 + 0.5
            Y0 = xy.getY() - fakeImage.getHeight()/2 + 0.5
            self.log.debug("Adding fake source at %d, %d" % (xy.getX(), xy.getY()))
            if sourceType == "galaxy":
                interpFakeImage = afwMath.offsetImage(fakeImage, X0, Y0, "lanczos3")
            else:
                interpFakeImage = fakeImage
 
            interpFakeImBBox = interpFakeImage.getBBox()
            interpFakeImBBox.clip(imageBBox)
 
            if interpFakeImBBox.getArea() > 0:
                imageMIView = imageMI[interpFakeImBBox]
                clippedFakeImage = interpFakeImage[interpFakeImBBox]
                clippedFakeImageMI = afwImage.MaskedImageF(clippedFakeImage)
                clippedFakeImageMI.mask.set(self.bitmask)
                imageMIView += clippedFakeImageMI
 
        return image
 

addPixCoords()

def lsst.pipe.tasks.insertFakes.addPixCoords	(		self,
			fakeCat,
			wcs
	)

Add pixel coordinates to the catalog of fakes.

Parameters
----------
fakeCat : `pandas.core.frame.DataFrame`
            The catalog of fake sources to be input
wcs : `lsst.afw.geom.SkyWcs`
            WCS to use to add fake sources

Returns
-------
fakeCat : `pandas.core.frame.DataFrame`

Notes
-----
The default option is to use the WCS information from the image. If the ``useUpdatedCalibs`` config
option is set then it will use the updated WCS from jointCal.

Definition at line 476 of file insertFakes.py.

    def addPixCoords(self, fakeCat, wcs):
 
        """Add pixel coordinates to the catalog of fakes.
 
        Parameters
        ----------
        fakeCat : `pandas.core.frame.DataFrame`
                    The catalog of fake sources to be input
        wcs : `lsst.afw.geom.SkyWcs`
                    WCS to use to add fake sources
 
        Returns
        -------
        fakeCat : `pandas.core.frame.DataFrame`
 
        Notes
        -----
        The default option is to use the WCS information from the image. If the ``useUpdatedCalibs`` config
        option is set then it will use the updated WCS from jointCal.
        """
 
        ras = fakeCat[self.config.raColName].values
        decs = fakeCat[self.config.decColName].values
        skyCoords = [SpherePoint(ra, dec, radians) for (ra, dec) in zip(ras, decs)]
        pixCoords = wcs.skyToPixel(skyCoords)
        xs = [coord.getX() for coord in pixCoords]
        ys = [coord.getY() for coord in pixCoords]
        fakeCat["x"] = xs
        fakeCat["y"] = ys
 
        return fakeCat
 

cleanCat()

def lsst.pipe.tasks.insertFakes.cleanCat	(		self,
			fakeCat,
			starCheckVal
	)

Remove rows from the fakes catalog which have HLR = 0 for either the buldge or disk component,
   also remove galaxies that have Sersic index outside the galsim min and max
   allowed (0.3 <= n <= 6.2).

Parameters
----------
fakeCat : `pandas.core.frame.DataFrame`
            The catalog of fake sources to be input
starCheckVal : `str`, `bytes` or `int`
            The value that is set in the sourceType column to specifiy an object is a star.

Returns
-------
fakeCat : `pandas.core.frame.DataFrame`
            The input catalog of fake sources but with the bad objects removed

Notes
-----
If the config option sourceSelectionColName is set then only objects with this column set to True
will be added.

Definition at line 665 of file insertFakes.py.

    def cleanCat(self, fakeCat, starCheckVal):
        """Remove rows from the fakes catalog which have HLR = 0 for either the buldge or disk component,
           also remove galaxies that have Sersic index outside the galsim min and max
           allowed (0.3 <= n <= 6.2).
 
        Parameters
        ----------
        fakeCat : `pandas.core.frame.DataFrame`
                    The catalog of fake sources to be input
        starCheckVal : `str`, `bytes` or `int`
                    The value that is set in the sourceType column to specifiy an object is a star.
 
        Returns
        -------
        fakeCat : `pandas.core.frame.DataFrame`
                    The input catalog of fake sources but with the bad objects removed
 
        Notes
        -----
        If the config option sourceSelectionColName is set then only objects with this column set to True
        will be added.
        """
 
        rowsToKeep = (((fakeCat[self.config.bulgeHLR] != 0.0) & (fakeCat[self.config.diskHLR] != 0.0))
                      | (fakeCat[self.config.sourceType] == starCheckVal))
        numRowsNotUsed = len(fakeCat) - len(np.where(rowsToKeep)[0])
        self.log.info("Removing %d rows with HLR = 0 for either the bulge or disk" % numRowsNotUsed)
        fakeCat = fakeCat[rowsToKeep]
 
        minN = galsim.Sersic._minimum_n
        maxN = galsim.Sersic._maximum_n
        rowsWithGoodSersic = (((fakeCat[self.config.nBulge] >= minN) & (fakeCat[self.config.nBulge] <= maxN)
                              & (fakeCat[self.config.nDisk] >= minN) & (fakeCat[self.config.nDisk] <= maxN))
                              | (fakeCat[self.config.sourceType] == starCheckVal))
        numRowsNotUsed = len(fakeCat) - len(np.where(rowsWithGoodSersic)[0])
        self.log.info("Removing %d rows of galaxies with nBulge or nDisk outside of %0.2f <= n <= %0.2f" %
                      (numRowsNotUsed, minN, maxN))
        fakeCat = fakeCat[rowsWithGoodSersic]
 
        if self.config.doSubSelectSources:
            try:
                rowsSelected = (fakeCat[self.config.sourceSelectionColName])
            except KeyError:
                raise KeyError("Given column, %s, for source selection not found." %
                               self.config.sourceSelectionColName)
            numRowsNotUsed = len(fakeCat) - len(rowsSelected)
            self.log.info("Removing %d rows which were not designated as template sources" % numRowsNotUsed)
            fakeCat = fakeCat[rowsSelected]
 
        return fakeCat
 

mkFakeGalsimGalaxies()

def lsst.pipe.tasks.insertFakes.mkFakeGalsimGalaxies	(		self,
			fakeCat,
			band,
			photoCalib,
			pixelScale,
			psf,
			image
	)

Make images of fake galaxies using GalSim.

Parameters
----------
band : `str`
pixelScale : `float`
psf : `lsst.meas.extensions.psfex.psfexPsf.PsfexPsf`
            The PSF information to use to make the PSF images
fakeCat : `pandas.core.frame.DataFrame`
            The catalog of fake sources to be input
photoCalib : `lsst.afw.image.photoCalib.PhotoCalib`
            Photometric calibration to be used to calibrate the fake sources

Yields
-------
galImages : `generator`
            A generator of tuples of `lsst.afw.image.exposure.exposure.ExposureF` and
            `lsst.geom.Point2D` of their locations.

Notes
-----

Fake galaxies are made by combining two sersic profiles, one for the bulge and one for the disk. Each
component has an individual sersic index (n), a, b and position angle (PA). The combined profile is
then convolved with the PSF at the specified x, y position on the image.

The names of the columns in the ``fakeCat`` are configurable and are the column names from the
University of Washington simulations database as default. For more information see the doc strings
attached to the config options.

See mkFakeStars doc string for an explanation of calibration to instrumental flux.

Definition at line 535 of file insertFakes.py.

    def mkFakeGalsimGalaxies(self, fakeCat, band, photoCalib, pixelScale, psf, image):
        """Make images of fake galaxies using GalSim.
 
        Parameters
        ----------
        band : `str`
        pixelScale : `float`
        psf : `lsst.meas.extensions.psfex.psfexPsf.PsfexPsf`
                    The PSF information to use to make the PSF images
        fakeCat : `pandas.core.frame.DataFrame`
                    The catalog of fake sources to be input
        photoCalib : `lsst.afw.image.photoCalib.PhotoCalib`
                    Photometric calibration to be used to calibrate the fake sources
 
        Yields
        -------
        galImages : `generator`
                    A generator of tuples of `lsst.afw.image.exposure.exposure.ExposureF` and
                    `lsst.geom.Point2D` of their locations.
 
        Notes
        -----
 
        Fake galaxies are made by combining two sersic profiles, one for the bulge and one for the disk. Each
        component has an individual sersic index (n), a, b and position angle (PA). The combined profile is
        then convolved with the PSF at the specified x, y position on the image.
 
        The names of the columns in the ``fakeCat`` are configurable and are the column names from the
        University of Washington simulations database as default. For more information see the doc strings
        attached to the config options.
 
        See mkFakeStars doc string for an explanation of calibration to instrumental flux.
        """
 
        self.log.info("Making %d fake galaxy images" % len(fakeCat))
 
        for (index, row) in fakeCat.iterrows():
            xy = geom.Point2D(row["x"], row["y"])
 
            # We put these two PSF calculations within this same try block so that we catch cases
            # where the object's position is outside of the image.
            try:
                correctedFlux = psf.computeApertureFlux(self.config.calibFluxRadius, xy)
                psfKernel = psf.computeKernelImage(xy).getArray()
                psfKernel /= correctedFlux
 
            except InvalidParameterError:
                self.log.info("Galaxy at %0.4f, %0.4f outside of image" % (row["x"], row["y"]))
                continue
 
            try:
                flux = photoCalib.magnitudeToInstFlux(row[self.config.magVar % band], xy)
            except LogicError:
                flux = 0
 
            bulge = galsim.Sersic(row[self.config.nBulge], half_light_radius=row[self.config.bulgeHLR])
            axisRatioBulge = row[self.config.bBulge]/row[self.config.aBulge]
            bulge = bulge.shear(q=axisRatioBulge, beta=((90 - row[self.config.paBulge])*galsim.degrees))
 
            disk = galsim.Sersic(row[self.config.nDisk], half_light_radius=row[self.config.diskHLR])
            axisRatioDisk = row[self.config.bDisk]/row[self.config.aDisk]
            disk = disk.shear(q=axisRatioDisk, beta=((90 - row[self.config.paDisk])*galsim.degrees))
 
            gal = disk + bulge
            gal = gal.withFlux(flux)
 
            psfIm = galsim.InterpolatedImage(galsim.Image(psfKernel), scale=pixelScale)
            gal = galsim.Convolve([gal, psfIm])
            try:
                galIm = gal.drawImage(scale=pixelScale, method="real_space").array
            except (galsim.errors.GalSimFFTSizeError, MemoryError):
                continue
 
            yield (afwImage.ImageF(galIm), xy)
 

mkFakeStars()

def lsst.pipe.tasks.insertFakes.mkFakeStars	(		self,
			fakeCat,
			band,
			photoCalib,
			psf,
			image
	)

Make fake stars based off the properties in the fakeCat.

Parameters
----------
band : `str`
psf : `lsst.meas.extensions.psfex.psfexPsf.PsfexPsf`
            The PSF information to use to make the PSF images
fakeCat : `pandas.core.frame.DataFrame`
            The catalog of fake sources to be input
image : `lsst.afw.image.exposure.exposure.ExposureF`
            The image into which the fake sources should be added
photoCalib : `lsst.afw.image.photoCalib.PhotoCalib`
            Photometric calibration to be used to calibrate the fake sources

Yields
-------
starImages : `generator`
            A generator of tuples of `lsst.afw.image.ImageF` of fake stars and
            `lsst.geom.Point2D` of their locations.

Notes
-----
To take a given magnitude and translate to the number of counts in the image
we use photoCalib.magnitudeToInstFlux, which returns the instrumental flux for the
given calibration radius used in the photometric calibration step.
Thus `calibFluxRadius` should be set to this same radius so that we can normalize
the PSF model to the correct instrumental flux within calibFluxRadius.

Definition at line 610 of file insertFakes.py.

    def mkFakeStars(self, fakeCat, band, photoCalib, psf, image):
 
        """Make fake stars based off the properties in the fakeCat.
 
        Parameters
        ----------
        band : `str`
        psf : `lsst.meas.extensions.psfex.psfexPsf.PsfexPsf`
                    The PSF information to use to make the PSF images
        fakeCat : `pandas.core.frame.DataFrame`
                    The catalog of fake sources to be input
        image : `lsst.afw.image.exposure.exposure.ExposureF`
                    The image into which the fake sources should be added
        photoCalib : `lsst.afw.image.photoCalib.PhotoCalib`
                    Photometric calibration to be used to calibrate the fake sources
 
        Yields
        -------
        starImages : `generator`
                    A generator of tuples of `lsst.afw.image.ImageF` of fake stars and
                    `lsst.geom.Point2D` of their locations.
 
        Notes
        -----
        To take a given magnitude and translate to the number of counts in the image
        we use photoCalib.magnitudeToInstFlux, which returns the instrumental flux for the
        given calibration radius used in the photometric calibration step.
        Thus `calibFluxRadius` should be set to this same radius so that we can normalize
        the PSF model to the correct instrumental flux within calibFluxRadius.
        """
 
        self.log.info("Making %d fake star images" % len(fakeCat))
 
        for (index, row) in fakeCat.iterrows():
            xy = geom.Point2D(row["x"], row["y"])
 
            # We put these two PSF calculations within this same try block so that we catch cases
            # where the object's position is outside of the image.
            try:
                correctedFlux = psf.computeApertureFlux(self.config.calibFluxRadius, xy)
                starIm = psf.computeImage(xy)
                starIm /= correctedFlux
 
            except InvalidParameterError:
                self.log.info("Star at %0.4f, %0.4f outside of image" % (row["x"], row["y"]))
                continue
 
            try:
                flux = photoCalib.magnitudeToInstFlux(row[self.config.magVar % band], xy)
            except LogicError:
                flux = 0
 
            starIm *= flux
            yield ((starIm.convertF(), xy))
 

trimFakeCat()

def lsst.pipe.tasks.insertFakes.trimFakeCat	(		self,
			fakeCat,
			image,
			wcs
	)

Trim the fake cat to about the size of the input image.

`fakeCat` must be processed with addPixCoords before using this method.

Parameters
----------
fakeCat : `pandas.core.frame.DataFrame`
            The catalog of fake sources to be input
image : `lsst.afw.image.exposure.exposure.ExposureF`
            The image into which the fake sources should be added
wcs : `lsst.afw.geom.SkyWcs`
            WCS to use to add fake sources

Returns
-------
fakeCat : `pandas.core.frame.DataFrame`
            The original fakeCat trimmed to the area of the image

Definition at line 508 of file insertFakes.py.

    def trimFakeCat(self, fakeCat, image, wcs):
        """Trim the fake cat to about the size of the input image.
 
        `fakeCat` must be processed with addPixCoords before using this method.
 
        Parameters
        ----------
        fakeCat : `pandas.core.frame.DataFrame`
                    The catalog of fake sources to be input
        image : `lsst.afw.image.exposure.exposure.ExposureF`
                    The image into which the fake sources should be added
        wcs : `lsst.afw.geom.SkyWcs`
                    WCS to use to add fake sources
 
        Returns
        -------
        fakeCat : `pandas.core.frame.DataFrame`
                    The original fakeCat trimmed to the area of the image
        """
 
        bbox = Box2D(image.getBBox())
 
        def trim(row):
            return bbox.dilatedBy(self.config.trimBuffer).contains(row["x"], row["y"])
 
        return fakeCat[fakeCat.apply(trim, axis=1)]
 

Variable Documentation

convIm

lsst.pipe.tasks.insertFakes.convIm = galsim.Convolve([galsimIm, psfIm])

Definition at line 452 of file insertFakes.py.

correctedFlux

lsst.pipe.tasks.insertFakes.correctedFlux = psf.computeApertureFlux(self.config.calibFluxRadius, xy)

raColName = pexConfig.Field(
    doc="RA column name used in the fake source catalog.",
    dtype=str,
    default="raJ2000",
)

decColName = pexConfig.Field(
    doc="Dec. column name used in the fake source catalog.",
    dtype=str,
    default="decJ2000",
)

doCleanCat = pexConfig.Field(
    doc="If true removes bad sources from the catalog.",
    dtype=bool,
    default=True,
)

diskHLR = pexConfig.Field(
    doc="Column name for the disk half light radius used in the fake source catalog.",
    dtype=str,
    default="DiskHalfLightRadius",
)

bulgeHLR = pexConfig.Field(
    doc="Column name for the bulge half light radius used in the fake source catalog.",
    dtype=str,
    default="BulgeHalfLightRadius",
)

magVar = pexConfig.Field(
    doc="The column name for the magnitude calculated taking variability into account. In the format "
        "``filter name``magVar, e.g. imagVar for the magnitude in the i band.",
    dtype=str,
    default="%smagVar",
)

nDisk = pexConfig.Field(
    doc="The column name for the sersic index of the disk component used in the fake source catalog.",
    dtype=str,
    default="disk_n",
)

nBulge = pexConfig.Field(
    doc="The column name for the sersic index of the bulge component used in the fake source catalog.",
    dtype=str,
    default="bulge_n",
)

aDisk = pexConfig.Field(
    doc="The column name for the semi major axis length of the disk component used in the fake source"
        "catalog.",
    dtype=str,
    default="a_d",
)

aBulge = pexConfig.Field(
    doc="The column name for the semi major axis length of the bulge component.",
    dtype=str,
    default="a_b",
)

bDisk = pexConfig.Field(
    doc="The column name for the semi minor axis length of the disk component.",
    dtype=str,
    default="b_d",
)

bBulge = pexConfig.Field(
    doc="The column name for the semi minor axis length of the bulge component used in the fake source "
        "catalog.",
    dtype=str,
    default="b_b",
)

paDisk = pexConfig.Field(
    doc="The column name for the PA of the disk component used in the fake source catalog.",
    dtype=str,
    default="pa_disk",
)

paBulge = pexConfig.Field(
    doc="The column name for the PA of the bulge component used in the fake source catalog.",
    dtype=str,
    default="pa_bulge",
)

sourceType = pexConfig.Field(
    doc="The column name for the source type used in the fake source catalog.",
    dtype=str,
    default="sourceType",
)

fakeType = pexConfig.Field(
    doc="What type of fake catalog to use, snapshot (includes variability in the magnitudes calculated "
        "from the MJD of the image), static (no variability) or filename for a user defined fits"
        "catalog.",
    dtype=str,
    default="static",
)

calibFluxRadius = pexConfig.Field(
    doc="Aperture radius (in pixels) that was used to define the calibration for this image+catalog. "
    "This will be used to produce the correct instrumental fluxes within the radius. "
    "This value should match that of the field defined in slot_CalibFlux_instFlux.",
    dtype=float,
    default=12.0,
)

coaddName = pexConfig.Field(
    doc="The name of the type of coadd used",
    dtype=str,
    default="deep",
)

doSubSelectSources = pexConfig.Field(
    doc="Set to True if you wish to sub select sources to be input based on the value in the column"
        "set in the sourceSelectionColName config option.",
    dtype=bool,
    default=False
)

sourceSelectionColName = pexConfig.Field(
    doc="The name of the column in the input fakes catalogue to be used to determine which sources to"
        "add, default is none and when this is used all sources are added.",
    dtype=str,
    default="templateSource"
)

insertImages = pexConfig.Field(
    doc="Insert images directly? True or False.",
    dtype=bool,
    default=False,
)

doProcessAllDataIds = pexConfig.Field(
    doc="If True, all input data IDs will be processed, even those containing no fake sources.",
    dtype=bool,
    default=False,
)

trimBuffer = pexConfig.Field(
    doc="Size of the pixel buffer surrounding the image. Only those fake sources with a centroid"
    "falling within the image+buffer region will be considered for fake source injection.",
    dtype=int,
    default=100,
)


class InsertFakesTask(PipelineTask, CmdLineTask):

Definition at line 442 of file insertFakes.py.

divIm

lsst.pipe.tasks.insertFakes.divIm = outIm/imSum

Definition at line 460 of file insertFakes.py.

flux

int lsst.pipe.tasks.insertFakes.flux = photoCalib.magnitudeToInstFlux(mag, xy)

Definition at line 463 of file insertFakes.py.

galsimIm

lsst.pipe.tasks.insertFakes.galsimIm = galsim.InterpolatedImage(galsim.Image(im.array), scale=pixelScale)

Definition at line 451 of file insertFakes.py.

imSum

lsst.pipe.tasks.insertFakes.imSum = np.sum(outIm)

Definition at line 459 of file insertFakes.py.

imWithFlux

lsst.pipe.tasks.insertFakes.imWithFlux = flux*divIm

Definition at line 467 of file insertFakes.py.

outIm

lsst.pipe.tasks.insertFakes.outIm = convIm.drawImage(scale=pixelScale, method="real_space").array

Definition at line 455 of file insertFakes.py.

psfIm

lsst.pipe.tasks.insertFakes.psfIm = galsim.InterpolatedImage(galsim.Image(psfKernel), scale=pixelScale)

Definition at line 450 of file insertFakes.py.

psfKernel

lsst.pipe.tasks.insertFakes.psfKernel = psf.computeKernelImage(xy).getArray()

Definition at line 443 of file insertFakes.py.