lsst.pipe.tasks.scaleZeroPoint.ScaleZeroPointTask Class Reference

Inheritance diagram for lsst.pipe.tasks.scaleZeroPoint.ScaleZeroPointTask:

Public Member Functions
	__init__ (self, *args, **kwargs)
	run (self, exposure, dataRef=None)
	computeImageScaler (self, exposure, dataRef=None)
	getPhotoCalib (self)
	scaleFromPhotoCalib (self, calib)
	scaleFromFluxMag0 (self, fluxMag0)

Static Public Attributes
	ConfigClass = ScaleZeroPointConfig

Protected Attributes
	_photoCalib

Static Protected Attributes
str	_DefaultName = "scaleZeroPoint"

Detailed Description

Compute scale factor to scale exposures to a desired photometric zero point.

This simple version assumes that the zero point is spatially invariant.

Definition at line 155 of file scaleZeroPoint.py.

Constructor & Destructor Documentation

__init__()

lsst.pipe.tasks.scaleZeroPoint.ScaleZeroPointTask.__init__	(		self,
		*	args,
		**	kwargs )

Reimplemented in lsst.pipe.tasks.scaleZeroPoint.SpatialScaleZeroPointTask.

Definition at line 164 of file scaleZeroPoint.py.

    def __init__(self, *args, **kwargs):
        pipeBase.Task.__init__(self, *args, **kwargs)
 
        # flux at mag=0 is 10^(zeroPoint/2.5)   because m = -2.5*log10(F/F0)
        fluxMag0 = 10**(0.4 * self.config.zeroPoint)
        self._photoCalib = afwImage.makePhotoCalibFromCalibZeroPoint(fluxMag0, 0.0)
 

Member Function Documentation

computeImageScaler()

lsst.pipe.tasks.scaleZeroPoint.ScaleZeroPointTask.computeImageScaler	(		self,
			exposure,
			dataRef = None )

Compute image scaling object for a given exposure.

Parameters
----------
exposure : `lsst.afw.image.Exposure`
    Exposure for which scaling is desired.
dataRef : `Unknown`, optional
    Data reference for exposure.
    Not used, but in API so that users can switch between spatially variant
    and invariant tasks.

Reimplemented in lsst.pipe.tasks.scaleZeroPoint.SpatialScaleZeroPointTask.

Definition at line 198 of file scaleZeroPoint.py.

    def computeImageScaler(self, exposure, dataRef=None):
        """Compute image scaling object for a given exposure.
 
        Parameters
        ----------
        exposure : `lsst.afw.image.Exposure`
            Exposure for which scaling is desired.
        dataRef : `Unknown`, optional
            Data reference for exposure.
            Not used, but in API so that users can switch between spatially variant
            and invariant tasks.
        """
        scale = self.scaleFromPhotoCalib(exposure.getPhotoCalib()).scale
        return ImageScaler(scale)
 

getPhotoCalib()

lsst.pipe.tasks.scaleZeroPoint.ScaleZeroPointTask.getPhotoCalib

(

self

)

Get desired PhotoCalib.

Returns
-------
calibration : `lsst.afw.image.PhotoCalib`
    Calibration with ``fluxMag0`` set appropriately for config.zeroPoint.

Definition at line 213 of file scaleZeroPoint.py.

    def getPhotoCalib(self):
        """Get desired PhotoCalib.
 
        Returns
        -------
        calibration : `lsst.afw.image.PhotoCalib`
            Calibration with ``fluxMag0`` set appropriately for config.zeroPoint.
        """
        return self._photoCalib
 

run()

lsst.pipe.tasks.scaleZeroPoint.ScaleZeroPointTask.run	(		self,
			exposure,
			dataRef = None )

Scale the specified exposure to the desired photometric zeropoint.

Parameters
----------
exposure : `lsst.afw.image.Exposure`
    Exposure to scale; masked image is scaled in place.
dataRef : `Unknown`
    Data reference for exposure.
    Not used, but in API so that users can switch between spatially variant
    and invariant tasks.

Returns
-------
result : `lsst.pipe.base.Struct`
    Results as a struct with attributes:

    ``imageScaler``
        The image scaling object used to scale exposure.

Reimplemented in lsst.pipe.tasks.scaleZeroPoint.SpatialScaleZeroPointTask.

Definition at line 171 of file scaleZeroPoint.py.

    def run(self, exposure, dataRef=None):
        """Scale the specified exposure to the desired photometric zeropoint.
 
        Parameters
        ----------
        exposure : `lsst.afw.image.Exposure`
            Exposure to scale; masked image is scaled in place.
        dataRef : `Unknown`
            Data reference for exposure.
            Not used, but in API so that users can switch between spatially variant
            and invariant tasks.
 
        Returns
        -------
        result : `lsst.pipe.base.Struct`
            Results as a struct with attributes:
 
            ``imageScaler``
                The image scaling object used to scale exposure.
        """
        imageScaler = self.computeImageScaler(exposure=exposure, dataRef=dataRef)
        mi = exposure.getMaskedImage()
        imageScaler.scaleMaskedImage(mi)
        return pipeBase.Struct(
            imageScaler=imageScaler,
        )
 

scaleFromFluxMag0()

lsst.pipe.tasks.scaleZeroPoint.ScaleZeroPointTask.scaleFromFluxMag0	(		self,
			fluxMag0 )

Compute the scale for the specified fluxMag0.

This is a wrapper around scaleFromPhotoCalib, which see for more information.

Parameters
----------
fluxMag0 : `float`
    Flux at magnitude zero.

Returns
-------
result : `lsst.pipe.base.Struct`
    Results as a struct with attributes:

    `scale`

    Scale, such that if pixelCalib describes the photometric zeropoint
    of a pixel then the following scales that pixel to the photometric
    zeropoint specified by config.zeroPoint:
        ``scale = computeScale(pixelCalib)``
        ``pixel *= scale``

Definition at line 247 of file scaleZeroPoint.py.

    def scaleFromFluxMag0(self, fluxMag0):
        """Compute the scale for the specified fluxMag0.
 
        This is a wrapper around scaleFromPhotoCalib, which see for more information.
 
        Parameters
        ----------
        fluxMag0 : `float`
            Flux at magnitude zero.
 
        Returns
        -------
        result : `lsst.pipe.base.Struct`
            Results as a struct with attributes:
 
            `scale`
 
            Scale, such that if pixelCalib describes the photometric zeropoint
            of a pixel then the following scales that pixel to the photometric
            zeropoint specified by config.zeroPoint:
                ``scale = computeScale(pixelCalib)``
                ``pixel *= scale``
        """
        calib = afwImage.makePhotoCalibFromCalibZeroPoint(fluxMag0, 0.0)
        return self.scaleFromPhotoCalib(calib)
 
 

scaleFromPhotoCalib()

lsst.pipe.tasks.scaleZeroPoint.ScaleZeroPointTask.scaleFromPhotoCalib	(		self,
			calib )

Compute the scale for the specified PhotoCalib.

Returns
-------
result : `lsst.pipe.base.Struct`
    Results as a struct with attributes:

    `scale`

        Scale, such that if pixelCalib describes the photometric
        zeropoint of a pixel then the following scales that pixel to
        the photometric zeropoint specified by config.zeroPoint:
            ``scale = computeScale(pixelCalib) pixel *= scale``

Notes
-----
Returns a struct to leave room for scaleErr in a future implementation.

Definition at line 223 of file scaleZeroPoint.py.

    def scaleFromPhotoCalib(self, calib):
        """Compute the scale for the specified PhotoCalib.
 
        Returns
        -------
        result : `lsst.pipe.base.Struct`
            Results as a struct with attributes:
 
            `scale`
 
                Scale, such that if pixelCalib describes the photometric
                zeropoint of a pixel then the following scales that pixel to
                the photometric zeropoint specified by config.zeroPoint:
                    ``scale = computeScale(pixelCalib) pixel *= scale``
 
        Notes
        -----
        Returns a struct to leave room for scaleErr in a future implementation.
        """
        fluxAtZeroPoint = calib.magnitudeToInstFlux(self.config.zeroPoint)
        return pipeBase.Struct(
            scale=1.0 / fluxAtZeroPoint,
        )
 

Member Data Documentation

_DefaultName

str lsst.pipe.tasks.scaleZeroPoint.ScaleZeroPointTask._DefaultName = "scaleZeroPoint"

staticprotected

Definition at line 162 of file scaleZeroPoint.py.

_photoCalib

lsst.pipe.tasks.scaleZeroPoint.ScaleZeroPointTask._photoCalib

protected

Definition at line 169 of file scaleZeroPoint.py.

ConfigClass

lsst.pipe.tasks.scaleZeroPoint.ScaleZeroPointTask.ConfigClass = ScaleZeroPointConfig

static

Definition at line 161 of file scaleZeroPoint.py.

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The documentation for this class was generated from the following file:

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/pipe_tasks/g14a832a312+ff425fae3c/python/lsst/pipe/tasks/scaleZeroPoint.py