MakePsfCandidatesTask

class lsst.meas.algorithms.MakePsfCandidatesTask(config: Optional[Config] = None, name: Optional[str] = None, parentTask: Optional[Task] = None, log: Optional[Union[logging.Logger, lsst.utils.logging.LsstLogAdapter]] = None)

Bases: lsst.pipe.base.Task

Create PSF candidates given an input catalog.

Methods Summary

emptyMetadata()	Empty (clear) the metadata for this Task and all sub-Tasks.
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.
makePsfCandidates(starCat, exposure)	Make a list of PSF candidates from a star catalog.
makeSubtask(name, **keyArgs)	Create a subtask as a new instance as the name attribute of this task.
run(starCat, exposure[, psfCandidateField])	Make a list of PSF candidates from a star catalog.
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.

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")

makePsfCandidates(starCat, exposure)

Make a list of PSF candidates from a star catalog.

Parameters:

starCat : lsst.afw.table.SourceCatalog

Catalog of stars, as returned by lsst.meas.algorithms.starSelector.run().

exposure : lsst.afw.image.Exposure

The exposure containing the sources.

Returns:

struct : lsst.pipe.base.Struct

Results struct containing:

• psfCandidates : List of PSF candidates

  (list of lsst.meas.algorithms.PsfCandidate).

• goodStarCat : Subset of starCat that was successfully made

  into PSF candidates (lsst.afw.table.SourceCatalog).

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.

run(starCat, exposure, psfCandidateField=None)

Make a list of PSF candidates from a star catalog.

Parameters:

starCat : lsst.afw.table.SourceCatalog

Catalog of stars, as returned by lsst.meas.algorithms.starSelector.run().

exposure : lsst.afw.image.Exposure

The exposure containing the sources.

psfCandidateField : str, optional

Name of flag field to set True for PSF candidates, or None to not set a field; the field is left unchanged for non-candidates.

Returns:

struct : lsst.pipe.base.Struct

Results struct containing:

• psfCandidates : List of PSF candidates

  (list of lsst.meas.algorithms.PsfCandidate).

• goodStarCat : Subset of starCat that was successfully made

  into PSF candidates (lsst.afw.table.SourceCatalog).

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