MatchOptimisticBTask

class lsst.meas.astrom.MatchOptimisticBTask(**kwargs)

Bases: lsst.pipe.base.Task

Match sources to reference objects using the Optimistic Pattern Matcher B algorithm of Tabur 2007.

Methods Summary

emptyMetadata() Empty (clear) the metadata for this Task and all sub-Tasks.
filterStars(refCat) Extra filtering pass; subclass if desired.
getFullMetadata() Get metadata for all tasks.
getFullName() Get the task name as a hierarchical name including parent task names.
getName() Get the name of the task.
getTaskDict() Get a dictionary of all tasks as a shallow copy.
makeField(doc) Make a lsst.pex.config.ConfigurableField for this task.
makeSubtask(name, **keyArgs) Create a subtask as a new instance as the name attribute of this task.
matchObjectsToSources(refCat, sourceCat, …) Match sources to position reference stars.
timer(name, logLevel) Context manager to log performance data for an arbitrary block of code.

Methods Documentation

emptyMetadata() → None

Empty (clear) the metadata for this Task and all sub-Tasks.

filterStars(refCat)

Extra filtering pass; subclass if desired.

Parameters:
refCat : lsst.afw.table.SimpleCatalog

Catalog of reference objects.

Returns:
trimmedRefCat : lsst.afw.table.SimpleCatalog

Reference catalog with some filtering applied. Currently no filtering is applied.

getFullMetadata() → lsst.pipe.base._task_metadata.TaskMetadata

Get metadata for all tasks.

Returns:
metadata : TaskMetadata

The keys are the full task name. Values are metadata for the top-level task and all subtasks, sub-subtasks, etc.

Notes

The returned metadata includes timing information (if @timer.timeMethod is used) and any metadata set by the task. The name of each item consists of the full task name with . replaced by :, followed by . and the name of the item, e.g.:

topLevelTaskName:subtaskName:subsubtaskName.itemName

using : in the full task name disambiguates the rare situation that a task has a subtask and a metadata item with the same name.

getFullName() → str

Get the task name as a hierarchical name including parent task names.

Returns:
fullName : str

The full name consists of the name of the parent task and each subtask separated by periods. For example:

  • The full name of top-level task “top” is simply “top”.
  • The full name of subtask “sub” of top-level task “top” is “top.sub”.
  • The full name of subtask “sub2” of subtask “sub” of top-level task “top” is “top.sub.sub2”.
getName() → str

Get the name of the task.

Returns:
taskName : str

Name of the task.

See also

getFullName
getTaskDict() → Dict[str, weakref.ReferenceType[lsst.pipe.base.task.Task]]

Get a dictionary of all tasks as a shallow copy.

Returns:
taskDict : dict

Dictionary containing full task name: task object for the top-level task and all subtasks, sub-subtasks, etc.

classmethod makeField(doc: str) → lsst.pex.config.configurableField.ConfigurableField

Make a lsst.pex.config.ConfigurableField for this task.

Parameters:
doc : str

Help text for the field.

Returns:
configurableField : lsst.pex.config.ConfigurableField

A ConfigurableField for this task.

Examples

Provides a convenient way to specify this task is a subtask of another task.

Here is an example of use:

class OtherTaskConfig(lsst.pex.config.Config):
    aSubtask = ATaskClass.makeField("brief description of task")
makeSubtask(name: str, **keyArgs) → None

Create a subtask as a new instance as the name attribute of this task.

Parameters:
name : str

Brief name of the subtask.

keyArgs

Extra keyword arguments used to construct the task. The following arguments are automatically provided and cannot be overridden:

  • “config”.
  • “parentTask”.

Notes

The subtask must be defined by Task.config.name, an instance of ConfigurableField or RegistryField.

matchObjectsToSources(refCat, sourceCat, wcs, sourceFluxField, refFluxField, match_tolerance=None)

Match sources to position reference stars.

Parameters:
refCat : lsst.afw.table.SimpleCatalog

Reference catalog to match.

sourceCat : lsst.afw.table.SourceCatalog

Catalog of sources found on an exposure. This should already be down-selected to “good”/”usable” sources in the calling Task.

wcs : lsst.afw.geom.SkyWcs

Current WCS of the exposure containing the sources.

sourceFluxField : str

Field of the sourceCat to use for flux

refFluxField : str

Field of the refCat to use for flux

match_tolerance : lsst.meas.astrom.MatchTolerance

Object containing information from previous lsst.meas.astrom.AstrometryTask match/fit cycles for use in matching. If None is config defaults.

Returns:
matchResult : lsst.pipe.base.Struct

Result struct with components

timer(name: str, logLevel: int = 10) → Iterator[None]

Context manager to log performance data for an arbitrary block of code.

Parameters:
name : str

Name of code being timed; data will be logged using item name: Start and End.

logLevel

A logging level constant.

See also

timer.logInfo

Examples

Creating a timer context:

with self.timer("someCodeToTime"):
    pass  # code to time