MatchPessimisticBConfig

class lsst.meas.astrom.MatchPessimisticBConfig

Bases: lsst.pex.config.config.Config

Configuration for MatchPessimisticBTask

Attributes Summary

history
matcherIterations	Number of softening iterations in matcher.
maxOffsetPix	Maximum allowed shift of WCS, due to matching (pixel).
maxRotationDeg	Rotation angle allowed between sources and position reference objects (degrees).
minFracMatchedPairs	Minimum number of matched pairs as a fraction of the smaller of the number of reference stars or the number of good sources; the actual minimum is the smaller of this value or minMatchedPairs.
minMatchDistPixels	Distance in units of pixels to always consider a source-reference pair a match.
minMatchedPairs	Minimum number of matched pairs; see also minFracMatchedPairs.
numBrightStars	Number of bright stars to use.
numPatternConsensus	Number of implied shift/rotations from patterns that must agree before it a given shift/rotation is accepted.
numPointsForShape	Number of points to define a shape for matching.
numPointsForShapeAttempt	Number of points to try for creating a shape.
sourceSelector	How to select sources for cross-matching.

Methods Summary

compare(other[, shortcut, rtol, atol, output])	!Compare two Configs for equality; return True if equal
formatHistory(name, **kwargs)	!Format the specified config field’s history to a more human-readable format
freeze()	!Make this Config and all sub-configs read-only
items()	!Return the list of (field name, field value) pairs
iteritems()	!Iterate over (field name, field value) pairs
iterkeys()	!Iterate over field names
itervalues()	!Iterate over field values
keys()	!Return the list of field names
load(filename[, root])	!Modify this config in place by executing the Python code in the named file.
loadFromStream(stream[, root, filename])	!Modify this config in place by executing the python code in the provided stream.
names()	!Return all the keys in a config recursively
save(filename[, root])	!Save a python script to the named file, which, when loaded, reproduces this Config
saveToStream(outfile[, root])	!Save a python script to a stream, which, when loaded, reproduces this Config
setDefaults()	Derived config classes that must compute defaults rather than using the Field defaults should do so here.
toDict()	!Return a dict of field name: value
update(**kw)	!Update values specified by the keyword arguments
validate()	!Validate the Config; raise an exception if invalid
values()	!Return the list of field values

Attributes Documentation

history

matcherIterations

Number of softening iterations in matcher. (int, default 5)

Valid Range = [1,inf)

maxOffsetPix

Maximum allowed shift of WCS, due to matching (pixel). When changing this value, the LoadReferenceObjectsConfig.pixelMargin should also be updated. (int, default 300)

Valid Range = [-inf,4000)

maxRotationDeg

Rotation angle allowed between sources and position reference objects (degrees). (float, default 1.0)

Valid Range = [-inf,6.0)

minFracMatchedPairs

Minimum number of matched pairs as a fraction of the smaller of the number of reference stars or the number of good sources; the actual minimum is the smaller of this value or minMatchedPairs. (float, default 0.3)

Valid Range = [0,1)

minMatchDistPixels

Distance in units of pixels to always consider a source-reference pair a match. This prevents the astrometric fitter from over-fitting and removing stars that should be matched and allows for inclusion of new matches as the wcs improves. (float, default 1.0)

Valid Range = [0.0,6.0)

minMatchedPairs

Minimum number of matched pairs; see also minFracMatchedPairs. (int, default 30)

Valid Range = [2,inf)

numBrightStars

Number of bright stars to use. Sets the max number of patterns that can be tested. (int, default 200)

Valid Range = [2,inf)

numPatternConsensus

Number of implied shift/rotations from patterns that must agree before it a given shift/rotation is accepted. This is only used after the first softening iteration fails and if both the number of reference and source objects is greater than numBrightStars. (int, default 3)

numPointsForShape

Number of points to define a shape for matching. (int, default 6)

numPointsForShapeAttempt

Number of points to try for creating a shape. This value should be greater than or equal to numPointsForShape. Besides loosening the signal to noise cut in the matcherSourceSelector, increasing this number will solve CCDs where no match was found. (int, default 6)

sourceSelector

How to select sources for cross-matching. The default matcherSourceSelector removes objects with low S/N, bad saturated objects, edge objects, and interpolated objects. (RegistryInstanceDict, default 'matcherPessimistic')

Methods Documentation

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

!Compare two Configs for equality; return True if equal

If the Configs contain RegistryFields or ConfigChoiceFields, unselected Configs will not be compared.

@param[in] other Config object to compare with self. @param[in] shortcut If True, return as soon as an inequality is found. @param[in] rtol Relative tolerance for floating point comparisons. @param[in] atol Absolute tolerance for floating point comparisons. @param[in] output If not None, a callable that takes a string, used (possibly repeatedly)

to report inequalities.

Floating point comparisons are performed by numpy.allclose; refer to that for details.

formatHistory(name, **kwargs)

!Format the specified config field’s history to a more human-readable format

@param[in] name name of field whose history is wanted @param[in] kwargs keyword arguments for lsst.pex.config.history.format @return a string containing the formatted history

freeze()

!Make this Config and all sub-configs read-only

items()

!Return the list of (field name, field value) pairs

iteritems()

!Iterate over (field name, field value) pairs

iterkeys()

!Iterate over field names

itervalues()

!Iterate over field values

keys()

!Return the list of field names

load(filename, root='config')

!Modify this config in place by executing the Python code in the named file.

@param[in] filename name of file containing config override code @param[in] root name of variable in file that refers to the config being overridden

For example: if the value of root is “config” and the file contains this text: “config.myField = 5” then this config’s field “myField” is set to 5.

@deprecated For purposes of 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.

@param[in] stream open file object, string or compiled string containing config override code @param[in] root name of variable in stream that refers to the config being overridden @param[in] filename name of config override file, or None if unknown or contained

in the stream; used for error reporting

For example: if the value of root is “config” and the stream contains this text: “config.myField = 5” then this config’s field “myField” is set to 5.

@deprecated For purposes of 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.

names()

!Return all the keys in a config recursively

save(filename, root='config')

!Save a python script to the named file, which, when loaded, reproduces this Config

@param[in] filename name of file to which to write the config @param[in] root name to use for the root config variable; the same value must be used when loading

saveToStream(outfile, root='config')

!Save a python script to a stream, which, when loaded, reproduces this Config

@param outfile [inout] open file object to which to write the config. Accepts strings not bytes. @param root [in] name to use for the root config variable; the same value must be used when loading

setDefaults()

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

toDict()

!Return a dict of field name: value

Correct behavior is dependent on proper implementation of Field.toDict. If implementing a new Field type, you may need to implement your own toDict method.

update(**kw)

!Update values specified by the keyword arguments

@warning 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. Modifying these keywords allows users to lie about a Config’s history. Please do not do so!

validate()

!Validate the Config; raise an exception if invalid

The base class implementation performs type checks on all fields by calling Field.validate().

Complex single-field validation can be defined by deriving new Field types. As syntactic sugar, some derived Field types are defined in this module which handle recursing into sub-configs (ConfigField, ConfigChoiceField)

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

values()

!Return the list of field values