ImageDifferenceConfig¶

class lsst.pipe.tasks.imageDifference.ImageDifferenceConfig¶

Bases: lsst.pex.config.Config

Config for ImageDifferenceTask

Attributes Summary

`astrometer`	astrometry task; used to match sources to reference objects, but not to fit a WCS (`ConfigurableInstance`, default `<class 'lsst.meas.astrom.astrometry.AstrometryConfig'>`)
`coaddName`	coadd name: typically one of deep, goodSeeing, or dcr (`str`, default `'deep'`)
`controlRandomSeed`	Random seed for shuffing the control sample (`int`, default `10`)
`controlStepSize`	What step size (every Nth one) to select a control sample from the kernelSources (`int`, default `5`)
`convolveTemplate`	Which image gets convolved (default = template) (`bool`, default `True`)
`decorrelate`	Decorrelate effects of A&L kernel convolution on image difference, only if doSubtract is True.
`detection`	Low-threshold detection for final measurement (`ConfigurableInstance`, default `<class 'lsst.meas.algorithms.detection.SourceDetectionConfig'>`)
`diaSourceMatchRadius`	Match radius (in arcseconds) for DiaSource to Source association (`float`, default `0.5`)
`doAddCalexpBackground`	Add background to calexp before processing it.
`doAddMetrics`	Add columns to the source table to hold analysis metrics? (`bool`, default `True`)
`doDebugRegister`	Writing debugging data for doUseRegister (`bool`, default `False`)
`doDecorrelation`	Perform diffim decorrelation to undo pixel correlation due to A&L kernel convolution? If True, also update the diffim PSF.
`doDetection`	Detect sources? (`bool`, default `True`)
`doDipoleFitting`	Measure dipoles using new algorithm? (`bool`, default `True`)
`doForcedMeasurement`	Force photometer diaSource locations on PVI? (`bool`, default `True`)
`doMatchSources`	Match diaSources with input calexp sources and ref catalog sources (`bool`, default `True`)
`doMeasurement`	Measure diaSources? (`bool`, default `True`)
`doMerge`	Merge positive and negative diaSources with grow radius set by growFootprint (`bool`, default `True`)
`doPreConvolve`	Convolve science image by its PSF before PSF-matching? (`bool`, default `True`)
`doScaleTemplateVariance`	Scale variance of the template before PSF matching (`bool`, default `False`)
`doSelectDcrCatalog`	Select stars of extreme color as part of the control sample (`bool`, default `False`)
`doSelectSources`	Select stars to use for kernel fitting (`bool`, default `True`)
`doSelectVariableCatalog`	Select stars that are variable to be part of the control sample (`bool`, default `False`)
`doSpatiallyVarying`	If using Zogy or A&L decorrelation, perform these on a grid across the image in order to allow for spatial variations (`bool`, default `False`)
`doSubtract`	Compute subtracted exposure? (`bool`, default `True`)
`doUseRegister`	Use image-to-image registration to align template with science image (`bool`, default `True`)
`doWriteMatchedExp`	Write warped and PSF-matched template coadd exposure? (`bool`, default `False`)
`doWriteSources`	Write sources? (`bool`, default `True`)
`doWriteSubtractedExp`	Write difference exposure? (`bool`, default `True`)
`forcedMeasurement`	Subtask to force photometer PVI at diaSource location.
`getTemplate`	Subtask to retrieve template exposure and sources (`ConfigurableInstance`, default `<class 'lsst.ip.diffim.getTemplate.GetCoaddAsTemplateConfig'>`)
`growFootprint`	Grow positive and negative footprints by this amount before merging (`int`, default `2`)
`history`
`kernelSourcesFromRef`	Select sources to measure kernel from reference catalog if True, template if false (`bool`, default `False`)
`measurement`	Enable updated dipole fitting method (`ConfigurableInstance`, default `<class 'lsst.ip.diffim.dipoleFitTask.DipoleFitTaskConfig'>`)
`refObjLoader`	reference object loader (`ConfigurableInstance`, default `<class 'lsst.meas.algorithms.loadIndexedReferenceObjects.LoadIndexedReferenceObjectsConfig'>`)
`register`	Task to enable image-to-image image registration (warping) (`ConfigurableInstance`, default `<class 'lsst.pipe.tasks.registerImage.RegisterConfig'>`)
`scaleVariance`	Subtask to rescale the variance of the template to the statistically expected level (`ConfigurableInstance`, default `<class 'lsst.pipe.tasks.scaleVariance.ScaleVarianceConfig'>`)
`sourceSelector`	Source selection algorithm (`ConfigurableInstance`, default `<class 'lsst.meas.algorithms.objectSizeStarSelector.ObjectSizeStarSelectorConfig'>`)
`subtract`	Subtraction Algorithm (`RegistryInstanceDict`, default `'al'`)
`templateSipOrder`	Sip Order for fitting the Template Wcs (default is too high, overfitting) (`int`, default `2`)
`useGaussianForPreConvolution`	Use a simple gaussian PSF model for pre-convolution (else use fit PSF)? Ignored if doPreConvolve false.

Methods Summary

`compare`(other[, shortcut, rtol, atol, output])	Compare this configuration to another `Config` for equality.
`formatHistory`(name, **kwargs)	Format a configuration field’s history to a human-readable format.
`freeze`()	Make this config, and all subconfigs, read-only.
`items`()	Get configurations as `(field name, field value)` pairs.
`iteritems`()	Iterate over (field name, field value) pairs.
`iterkeys`()	Iterate over field names
`itervalues`()	Iterate over field values.
`keys`()	Get field names.
`load`(filename[, root])	Modify this config in place by executing the Python code in a configuration file.
`loadFromStream`(stream[, root, filename])	Modify this Config in place by executing the Python code in the provided stream.
`names`()	Get all the field names in the config, recursively.
`save`(filename[, root])	Save a Python script to the named file, which, when loaded, reproduces this config.
`saveToStream`(outfile[, root, skipImports])	Save a configuration file to a stream, which, when loaded, reproduces this config.
`setDefaults`()	Subclass hook for computing defaults.
`toDict`()	Make a dictionary of field names and their values.
`update`(**kw)	Update values of fields specified by the keyword arguments.
`validate`()	Validate the Config, raising an exception if invalid.
`values`()	Get field values.

Attributes Documentation

astrometer¶: astrometry task; used to match sources to reference objects, but not to fit a WCS (ConfigurableInstance, default <class 'lsst.meas.astrom.astrometry.AstrometryConfig'>)

coaddName¶: coadd name: typically one of deep, goodSeeing, or dcr (str, default 'deep')

controlRandomSeed¶: Random seed for shuffing the control sample (int, default 10)

controlStepSize¶: What step size (every Nth one) to select a control sample from the kernelSources (int, default 5)

convolveTemplate¶: Which image gets convolved (default = template) (bool, default True)

decorrelate¶: Decorrelate effects of A&L kernel convolution on image difference, only if doSubtract is True. If this option is enabled, then detection.thresholdValue should be set to 5.0 (rather than the default of 5.5). (ConfigurableInstance, default <class 'lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelSpatialConfig'>)

detection¶: Low-threshold detection for final measurement (ConfigurableInstance, default <class 'lsst.meas.algorithms.detection.SourceDetectionConfig'>)

diaSourceMatchRadius¶: Match radius (in arcseconds) for DiaSource to Source association (float, default 0.5)

doAddCalexpBackground¶: Add background to calexp before processing it. Useful as ipDiffim does background matching. (bool, default False)

doAddMetrics¶: Add columns to the source table to hold analysis metrics? (bool, default True)

doDebugRegister¶: Writing debugging data for doUseRegister (bool, default False)

doDecorrelation¶: Perform diffim decorrelation to undo pixel correlation due to A&L kernel convolution? If True, also update the diffim PSF. (bool, default False)

doDetection¶: Detect sources? (bool, default True)

doDipoleFitting¶: Measure dipoles using new algorithm? (bool, default True)

doForcedMeasurement¶: Force photometer diaSource locations on PVI? (bool, default True)

doMatchSources¶: Match diaSources with input calexp sources and ref catalog sources (bool, default True)

doMeasurement¶: Measure diaSources? (bool, default True)

doMerge¶: Merge positive and negative diaSources with grow radius set by growFootprint (bool, default True)

doPreConvolve¶: Convolve science image by its PSF before PSF-matching? (bool, default True)

doScaleTemplateVariance¶: Scale variance of the template before PSF matching (bool, default False)

doSelectDcrCatalog¶: Select stars of extreme color as part of the control sample (bool, default False)

doSelectSources¶: Select stars to use for kernel fitting (bool, default True)

doSelectVariableCatalog¶: Select stars that are variable to be part of the control sample (bool, default False)

doSpatiallyVarying¶: If using Zogy or A&L decorrelation, perform these on a grid across the image in order to allow for spatial variations (bool, default False)

doSubtract¶: Compute subtracted exposure? (bool, default True)

doUseRegister¶: Use image-to-image registration to align template with science image (bool, default True)

doWriteMatchedExp¶: Write warped and PSF-matched template coadd exposure? (bool, default False)

doWriteSources¶: Write sources? (bool, default True)

doWriteSubtractedExp¶: Write difference exposure? (bool, default True)

forcedMeasurement¶: Subtask to force photometer PVI at diaSource location. (ConfigurableInstance, default <class 'lsst.meas.base.forcedMeasurement.ForcedMeasurementConfig'>)

getTemplate¶: Subtask to retrieve template exposure and sources (ConfigurableInstance, default <class 'lsst.ip.diffim.getTemplate.GetCoaddAsTemplateConfig'>)

growFootprint¶: Grow positive and negative footprints by this amount before merging (int, default 2)

history¶

kernelSourcesFromRef¶: Select sources to measure kernel from reference catalog if True, template if false (bool, default False)

measurement¶: Enable updated dipole fitting method (ConfigurableInstance, default <class 'lsst.ip.diffim.dipoleFitTask.DipoleFitTaskConfig'>)

refObjLoader¶: reference object loader (ConfigurableInstance, default <class 'lsst.meas.algorithms.loadIndexedReferenceObjects.LoadIndexedReferenceObjectsConfig'>)

register¶: Task to enable image-to-image image registration (warping) (ConfigurableInstance, default <class 'lsst.pipe.tasks.registerImage.RegisterConfig'>)

scaleVariance¶: Subtask to rescale the variance of the template to the statistically expected level (ConfigurableInstance, default <class 'lsst.pipe.tasks.scaleVariance.ScaleVarianceConfig'>)

sourceSelector¶: Source selection algorithm (ConfigurableInstance, default <class 'lsst.meas.algorithms.objectSizeStarSelector.ObjectSizeStarSelectorConfig'>)

subtract¶: Subtraction Algorithm (RegistryInstanceDict, default 'al')

templateSipOrder¶: Sip Order for fitting the Template Wcs (default is too high, overfitting) (int, default 2)

useGaussianForPreConvolution¶: Use a simple gaussian PSF model for pre-convolution (else use fit PSF)? Ignored if doPreConvolve false. (bool, default True)

Methods Documentation

compare(other, shortcut=True, rtol=1e-08, atol=1e-08, output=None)¶

Compare this configuration to another Config for equality.

Parameters:

other : lsst.pex.config.Config: Other Config object to compare against this config.
shortcut : bool, optional: If True, return as soon as an inequality is found. Default is True.
rtol : float, optional: Relative tolerance for floating point comparisons.
atol : float, optional: Absolute tolerance for floating point comparisons.
output : callable, optional: A callable that takes a string, used (possibly repeatedly) to report inequalities.

Returns:

isEqual : bool: True when the two lsst.pex.config.Config instances are equal. False if there is an inequality.

See also

lsst.pex.config.compareConfigs

Notes

Unselected targets of RegistryField fields and unselected choices of ConfigChoiceField fields are not considered by this method.

Floating point comparisons are performed by numpy.allclose.

formatHistory(name, **kwargs)¶

Format a configuration field’s history to a human-readable format.

Parameters:	name : `str` Name of a `Field` in this config. kwargs Keyword arguments passed to `lsst.pex.config.history.format`.
Returns:	history : `str` A string containing the formatted history.

See also

lsst.pex.config.history.format

freeze()¶: Make this config, and all subconfigs, read-only.

items()¶

Get configurations as (field name, field value) pairs.

Returns:	items : `list` List of tuples for each configuration. Tuple items are: Field name. Field value.

See also

lsst.pex.config.Config.iteritems

iteritems()¶

Iterate over (field name, field value) pairs.

Yields:	item : `tuple` Tuple items are: Field name. Field value.

See also

lsst.pex.config.Config.items

iterkeys()¶

Iterate over field names

Yields:	key : `str` A field’s key (attribute name).

See also

lsst.pex.config.Config.values

itervalues()¶

Iterate over field values.

Yields:	value : obj A field value.

See also

lsst.pex.config.Config.values

keys()¶

Get field names.

Returns:	names : `list` List of `lsst.pex.config.Field` names.

See also

lsst.pex.config.Config.iterkeys

load(filename, root='config')¶

Modify this config in place by executing the Python code in a configuration file.

Parameters:

filename : str

Name of the configuration file. A configuration file is Python module.

root : str, optional

Name of the variable in file that refers to the config being overridden.

For example, the value of root is "config" and the file contains:

config.myField = 5

Then this config’s field myField is set to 5.

Deprecated: For backwards compatibility, older config files that use root="root" instead of root="config" will be loaded with a warning printed to sys.stderr. This feature will be removed at some point.

See also

lsst.pex.config.Config.loadFromStream, lsst.pex.config.Config.save, lsst.pex.config.Config.saveFromStream

loadFromStream(stream, root='config', filename=None)¶

Modify this Config in place by executing the Python code in the provided stream.

Parameters:

stream : file-like object, str, or compiled string

Stream containing configuration override code.

root : str, optional

Name of the variable in file that refers to the config being overridden.

For example, the value of root is "config" and the file contains:

config.myField = 5

Then this config’s field myField is set to 5.

Deprecated: For backwards compatibility, older config files that use root="root" instead of root="config" will be loaded with a warning printed to sys.stderr. This feature will be removed at some point.

filename : str, optional

Name of the configuration file, or None if unknown or contained in the stream. Used for error reporting.

See also

lsst.pex.config.Config.load, lsst.pex.config.Config.save, lsst.pex.config.Config.saveFromStream

names()¶

Get all the field names in the config, recursively.

Returns:	names : `list` of `str` Field names.

save(filename, root='config')¶

Save a Python script to the named file, which, when loaded, reproduces this config.

Parameters:	filename : `str` Desination filename of this configuration. root : `str`, optional Name to use for the root config variable. The same value must be used when loading (see `lsst.pex.config.Config.load`).

saveToStream(outfile, root='config', skipImports=False)¶

Save a configuration file to a stream, which, when loaded, reproduces this config.

Parameters:

outfile : file-like object: Destination file object write the config into. Accepts strings not bytes.
root: Name to use for the root config variable. The same value must be used when loading (see lsst.pex.config.Config.load).
skipImports : bool, optional: If True then do not include import statements in output, this is to support human-oriented output from pipetask where additional clutter is not useful.

setDefaults()¶

Subclass hook for computing defaults.

Notes

Derived Config classes that must compute defaults rather than using the Field instances’s defaults should do so here. To correctly use inherited defaults, implementations of setDefaults must call their base class’s setDefaults.

toDict()¶

Make a dictionary of field names and their values.

Returns:	dict_ : `dict` Dictionary with keys that are `Field` names. Values are `Field` values.

See also

lsst.pex.config.Field.toDict

Notes

This method uses the toDict method of individual fields. Subclasses of Field may need to implement a toDict method for this method to work.

update(**kw)¶

Update values of fields specified by the keyword arguments.

Parameters:	kw Keywords are configuration field names. Values are configuration field values.

Notes

The __at and __label keyword arguments are special internal keywords. They are used to strip out any internal steps from the history tracebacks of the config. Do not modify these keywords to subvert a Config instance’s history.

Examples

This is a config with three fields:

>>> from lsst.pex.config import Config, Field
>>> class DemoConfig(Config):
...     fieldA = Field(doc='Field A', dtype=int, default=42)
...     fieldB = Field(doc='Field B', dtype=bool, default=True)
...     fieldC = Field(doc='Field C', dtype=str, default='Hello world')
...
>>> config = DemoConfig()

These are the default values of each field:

>>> for name, value in config.iteritems():
...     print(f"{name}: {value}")
...
fieldA: 42
fieldB: True
fieldC: 'Hello world'

Using this method to update fieldA and fieldC:

>>> config.update(fieldA=13, fieldC='Updated!')

Now the values of each field are:

>>> for name, value in config.iteritems():
...     print(f"{name}: {value}")
...
fieldA: 13
fieldB: True
fieldC: 'Updated!'

validate()¶

Validate the Config, raising an exception if invalid.

Raises:	lsst.pex.config.FieldValidationError Raised if verification fails.

Notes

The base class implementation performs type checks on all fields by calling their validate methods.

Complex single-field validation can be defined by deriving new Field types. For convenience, some derived lsst.pex.config.Field-types (ConfigField and ConfigChoiceField) are defined in lsst.pex.config that handle recursing into subconfigs.

Inter-field relationships should only be checked in derived Config classes after calling this method, and base validation is complete.

values()¶

Get field values.

Returns:	values : `list` List of field values.

See also

lsst.pex.config.Config.itervalues

Navigation

ImageDifferenceConfig¶