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)
doEvalLocCalibration Store calibration products (local wcs and photoCalib) in the output DiaSource catalog.
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)
evalLocCalib Task to strip calibrations from an exposure and store their local values in the output DiaSource catalog.
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)

doEvalLocCalibration

Store calibration products (local wcs and photoCalib) in the output DiaSource catalog. (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)

evalLocCalib

Task to strip calibrations from an exposure and store their local values in the output DiaSource catalog. (ConfigurableInstance, default <class 'lsst.meas.base.evaluateLocalCalibration.EvaluateLocalCalibrationConfig'>)

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.

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.

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:

  1. Field name.
  2. Field value.
iteritems()

Iterate over (field name, field value) pairs.

Yields:
item : tuple

Tuple items are:

  1. Field name.
  2. Field value.
iterkeys()

Iterate over field names

Yields:
key : str

A field’s key (attribute name).

itervalues()

Iterate over field values.

Yields:
value : obj

A field value.

keys()

Get field names.

Returns:
names : list

List of lsst.pex.config.Field names.

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.

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.