SourceDeblendConfig

class lsst.meas.deblender.SourceDeblendConfig

Bases: lsst.pex.config.Config

Attributes Summary

assignStrayFlux Assign stray flux (not claimed by any child in the deblender) to deblend children.
catchFailures If True, catch exceptions thrown by the deblender, log them, and set a flag on the parent, instead of letting them propagate up (bool, default False)
ciDeblendChildRange Only deblend parent Footprints with a number of peaks in the (inclusive) range indicated.If useCiLimits==False then this parameter is ignored.
ciNumParentsToDeblend Only use the first ciNumParentsToDeblend parent footprints with a total peak count within ciDebledChildRange.
clipStrayFluxFraction When splitting stray flux, clip fractions below this value to zero.
edgeHandling What to do when a peak to be deblended is close to the edge of the image (str, default 'ramp')
history
maskLimits Mask planes with the corresponding limit on the fraction of masked pixels.
maskPlanes Mask planes to ignore when performing statistics (List, default ['SAT', 'INTRP', 'NO_DATA'])
maxFootprintArea Maximum area for footprints before they are ignored as large; non-positive means no threshold applied (int, default 1000000)
maxFootprintSize Maximum linear dimension for footprints before they are ignored as large; non-positive means no threshold applied (int, default 0)
maxNumberOfPeaks Only deblend the brightest maxNumberOfPeaks peaks in the parent (<= 0: unlimited) (int, default 0)
maxTempDotProd If the dot product between two templates is larger than this value, we consider them to be describing the same object (i.e.
medianSmoothTemplate Apply a smoothing filter to all of the template images (bool, default True)
minFootprintAxisRatio Minimum axis ratio for footprints before they are ignored as large; non-positive means no threshold applied (float, default 0.0)
notDeblendedMask Mask name for footprints not deblended, or None (str, default 'NOT_DEBLENDED')
propagateAllPeaks Guarantee that all peaks produce a child source.
psfChisq1 Chi-squared per DOF cut for deciding a source is a PSF during deblending (un-shifted PSF model) (float, default 1.5)
psfChisq2 Chi-squared per DOF cut for deciding a source is PSF during deblending (shifted PSF model) (float, default 1.5)
psfChisq2b Chi-squared per DOF cut for deciding a source is a PSF during deblending (shifted PSF model #2) (float, default 1.5)
removeDegenerateTemplates Try to remove similar templates? (bool, default False)
strayFluxRule How to split flux among peaks (str, default 'trim')
strayFluxToPointSources When the deblender should attribute stray flux to point sources (str, default 'necessary')
tinyFootprintSize Footprints smaller in width or height than this value will be ignored; minimum of 2 due to PSF gradient calculation.
useCiLimits Limit the number of sources deblended for CI to prevent long build times (bool, default False)
weightTemplates If true, a least-squares fit of the templates will be done to the full image.

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

assignStrayFlux

Assign stray flux (not claimed by any child in the deblender) to deblend children. (bool, default True)

catchFailures

If True, catch exceptions thrown by the deblender, log them, and set a flag on the parent, instead of letting them propagate up (bool, default False)

ciDeblendChildRange

Only deblend parent Footprints with a number of peaks in the (inclusive) range indicated.If useCiLimits==False then this parameter is ignored. (List, default [2, 10])

ciNumParentsToDeblend

Only use the first ciNumParentsToDeblend parent footprints with a total peak count within ciDebledChildRange. If useCiLimits==False then this parameter is ignored. (int, default 10)

clipStrayFluxFraction

When splitting stray flux, clip fractions below this value to zero. (float, default 0.001)

edgeHandling

What to do when a peak to be deblended is close to the edge of the image (str, default 'ramp')

Allowed values:

'clip'
Clip the template at the edge AND the mirror of the edge.
'ramp'
Ramp down flux at the image edge by the PSF
'noclip'
Ignore the edge when building the symmetric template.
'None'
Field is optional
history
maskLimits

Mask planes with the corresponding limit on the fraction of masked pixels. Sources violating this limit will not be deblended. (Dict, default {})

maskPlanes

Mask planes to ignore when performing statistics (List, default ['SAT', 'INTRP', 'NO_DATA'])

maxFootprintArea

Maximum area for footprints before they are ignored as large; non-positive means no threshold applied (int, default 1000000)

maxFootprintSize

Maximum linear dimension for footprints before they are ignored as large; non-positive means no threshold applied (int, default 0)

maxNumberOfPeaks

Only deblend the brightest maxNumberOfPeaks peaks in the parent (<= 0: unlimited) (int, default 0)

maxTempDotProd

If the dot product between two templates is larger than this value, we consider them to be describing the same object (i.e. they are degenerate). If one of the objects has been labeled as a PSF it will be removed, otherwise the template with the lowest value will be removed. (float, default 0.5)

medianSmoothTemplate

Apply a smoothing filter to all of the template images (bool, default True)

minFootprintAxisRatio

Minimum axis ratio for footprints before they are ignored as large; non-positive means no threshold applied (float, default 0.0)

notDeblendedMask

Mask name for footprints not deblended, or None (str, default 'NOT_DEBLENDED')

propagateAllPeaks

Guarantee that all peaks produce a child source. (bool, default False)

psfChisq1

Chi-squared per DOF cut for deciding a source is a PSF during deblending (un-shifted PSF model) (float, default 1.5)

psfChisq2

Chi-squared per DOF cut for deciding a source is PSF during deblending (shifted PSF model) (float, default 1.5)

psfChisq2b

Chi-squared per DOF cut for deciding a source is a PSF during deblending (shifted PSF model #2) (float, default 1.5)

removeDegenerateTemplates

Try to remove similar templates? (bool, default False)

strayFluxRule

How to split flux among peaks (str, default 'trim')

Allowed values:

'r-to-peak'
~ 1/(1+R^2) to the peak
'r-to-footprint'
~ 1/(1+R^2) to the closest pixel in the footprint. CAUTION: this can be computationally expensive on large footprints!
'nearest-footprint'
Assign 100% to the nearest footprint (using L-1 norm aka Manhattan distance)
'trim'
Shrink the parent footprint to pixels that are not assigned to children
'None'
Field is optional
strayFluxToPointSources

When the deblender should attribute stray flux to point sources (str, default 'necessary')

Allowed values:

'necessary'
When there is not an extended object in the footprint
'always'
Always
'never'
Never; stray flux will not be attributed to any deblended child if the deblender thinks all peaks look like point sources
'None'
Field is optional
tinyFootprintSize

Footprints smaller in width or height than this value will be ignored; minimum of 2 due to PSF gradient calculation. (int, default 2)

Valid Range = [2,inf)

useCiLimits

Limit the number of sources deblended for CI to prevent long build times (bool, default False)

weightTemplates

If true, a least-squares fit of the templates will be done to the full image. The templates will be re-weighted based on this fit. (bool, default False)

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.