PcaPsfDeterminerConfig¶

class lsst.meas.algorithms.PcaPsfDeterminerConfig¶

Bases: lsst.meas.algorithms.BasePsfDeterminerConfig

Attributes Summary

`borderWidth`	Number of pixels to ignore around the edge of PSF candidate postage stamps (`int`, default `0`)
`constantWeight`	Should each PSF candidate be given the same weight, independent of magnitude? (`bool`, default `True`)
`doMaskBlends`	Mask blends in image? (`bool`, default `True`)
`doRejectBlends`	Reject candidates that are blended? (`bool`, default `False`)
`history`
`kernelSize`	radius of the kernel to create, relative to the square root of the stellar quadrupole moments (`float`, default `10.0`)
`kernelSizeMax`	Maximum radius of the kernel (`int`, default `45`)
`kernelSizeMin`	Minimum radius of the kernel (`int`, default `25`)
`lam`	floor for variance is lam*data (`float`, default `0.05`)
`nEigenComponents`	number of eigen components for PSF kernel creation (`int`, default `4`)
`nIterForPsf`	number of iterations of PSF candidate star list (`int`, default `3`)
`nStarPerCell`	number of stars per psf cell for PSF kernel creation (`int`, default `3`)
`nStarPerCellSpatialFit`	number of stars per psf Cell for spatial fitting (`int`, default `5`)
`nonLinearSpatialFit`	Use non-linear fitter for spatial variation of Kernel (`bool`, default `False`)
`pixelThreshold`	Threshold (stdev) for rejecting extraneous pixels around candidate; applied if positive (`float`, default `0.0`)
`reducedChi2ForPsfCandidates`	for psf candidate evaluation (`float`, default `2.0`)
`sizeCellX`	size of cell used to determine PSF (pixels, column direction) (`int`, default `256`)
`sizeCellY`	size of cell used to determine PSF (pixels, row direction) (`int`, default `256`)
`spatialOrder`	specify spatial order for PSF kernel creation (`int`, default `2`)
`spatialReject`	Rejection threshold (stdev) for candidates based on spatial fit (`float`, default `3.0`)
`tolerance`	tolerance of spatial fitting (`float`, default `0.01`)

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.
`loadFromString`(code[, root, filename])	Modify this Config in place by executing the Python code in the provided string.
`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.
`saveToString`([skipImports])	Return the Python script form of this configuration as an executable string.
`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

borderWidth¶: Number of pixels to ignore around the edge of PSF candidate postage stamps (int, default 0)

constantWeight¶: Should each PSF candidate be given the same weight, independent of magnitude? (bool, default True)

doMaskBlends¶: Mask blends in image? (bool, default True)

doRejectBlends¶: Reject candidates that are blended? (bool, default False)

history¶

kernelSize¶: radius of the kernel to create, relative to the square root of the stellar quadrupole moments (float, default 10.0)

kernelSizeMax¶: Maximum radius of the kernel (int, default 45)

kernelSizeMin¶: Minimum radius of the kernel (int, default 25)

lam¶: floor for variance is lam*data (float, default 0.05)

nEigenComponents¶: number of eigen components for PSF kernel creation (int, default 4)

nIterForPsf¶: number of iterations of PSF candidate star list (int, default 3)

nStarPerCell¶: number of stars per psf cell for PSF kernel creation (int, default 3)

nStarPerCellSpatialFit¶: number of stars per psf Cell for spatial fitting (int, default 5)

nonLinearSpatialFit¶: Use non-linear fitter for spatial variation of Kernel (bool, default False)

pixelThreshold¶: Threshold (stdev) for rejecting extraneous pixels around candidate; applied if positive (float, default 0.0)

reducedChi2ForPsfCandidates¶: for psf candidate evaluation (float, default 2.0)

sizeCellX¶: size of cell used to determine PSF (pixels, column direction) (int, default 256)

sizeCellY¶: size of cell used to determine PSF (pixels, row direction) (int, default 256)

spatialOrder¶: specify spatial order for PSF kernel creation (int, default 2)

spatialReject¶: Rejection threshold (stdev) for candidates based on spatial fit (float, default 3.0)

tolerance¶: tolerance of spatial fitting (float, default 0.01)

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.

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, bytes, or compiled string

Stream containing configuration override code. If this is a code object, it should be compiled with mode="exec".

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.

Notes

For backwards compatibility reasons, this method accepts strings, bytes and code objects as well as file-like objects. New code should use loadFromString instead for most of these types.

loadFromString(code, root='config', filename=None)¶

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

Parameters:

code : str, bytes, 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.

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.

saveToString(skipImports=False)¶

Return the Python script form of this configuration as an executable string.

Parameters:	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.
Returns:	code : `str` A code string readable by `loadFromString`.

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

PcaPsfDeterminerConfig¶