BasePsfDeterminerTask¶

class lsst.meas.algorithms.BasePsfDeterminerTask(config, schema=None, **kwds)¶

Bases: Task

Base class for PSF determiners

Register all PSF determiners with the psfDeterminerRegistry using:: psfDeterminerRegistry.register(name, class)

Parameters:

configlsst.pexConfig.Config: Input for configuring the algorithm
schemalsst.afw.table.Schema: Schema used for sources; passing a schema allows the determiner to reserve a flag field to mark stars used in PSF measurement, but some PSF determiners ignore this argument.

Attributes Summary

usesMatches

Methods Summary

`determinePsf`(exposure, psfCandidateList[, ...])	Determine a PSF model.
`downsampleCandidates`(inputCandidateList)	Down-sample candidates from the input candidate list.
`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.
`makeSubtask`(name, **keyArgs)	Create a subtask as a new instance as the `name` attribute of this task.
`timer`(name[, logLevel])	Context manager to log performance data for an arbitrary block of code.

Attributes Documentation

usesMatches = False¶

Methods Documentation

abstract determinePsf(exposure, psfCandidateList, metadata=None, flagKey=None)¶

Determine a PSF model.

Parameters:

exposurelsst.afw.Exposure: Exposure containing the psf candidates.
psdCandidateListlist [lsst.meas.algorithms.PsfCandidate]: A sequence of PSF candidates; typically obtained by detecting sources and then running them through a star selector.
metadatastr, optional: A place to save interesting items.
flagKey: `lsst.afw.table.Key`, optional: Schema key used to mark sources actually used in PSF determination.

Returns:

psflsst.afw.detection.Psf: The fit PSF.
cellSetlsst.afw.math.SpatialCellSet: The spatial cell set used to determine the PSF

downsampleCandidates(inputCandidateList)¶

Down-sample candidates from the input candidate list.

Parameters:

inputCandidateListlist [lsst.meas.algorithms.PsfCandidate]: Input candidate list.

Returns:

outputCandidateListlist [lsst.meas.algorithms.PsfCandidate]: Down-selected candidate list.

emptyMetadata() → None¶: Empty (clear) the metadata for this Task and all sub-Tasks.

getFullMetadata() → TaskMetadata¶

Get metadata for all tasks.

Returns:

metadataTaskMetadata: 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:

fullNamestr

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:

taskNamestr: Name of the task.

See also

getFullName: Get the full name of the task.

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

Get a dictionary of all tasks as a shallow copy.

Returns:

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

classmethod makeField(doc: str) → ConfigurableField¶

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

Parameters:

docstr: Help text for the field.

Returns:

configurableFieldlsst.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: Any) → None¶

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

Parameters:

namestr

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.

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

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

Parameters:

namestr: Name of code being timed; data will be logged using item name: Start and End.
logLevelint: A logging level constant.

Navigation

BasePsfDeterminerTask¶