FlaggedSourceSelectorTask

class lsst.meas.algorithms.FlaggedSourceSelectorTask(**kwargs)

Bases: lsst.meas.algorithms.BaseSourceSelectorTask

A trivial SourceSelector that simply uses an existing flag field to filter a SourceCatalog.

This is most frequently used in steps that occur after the a PSF model has been built, to allow other procedures that need Sources to use the set of Sources used to determine the PSF.

Attributes:
usesMatches : bool

A boolean variable specify if the inherited source selector uses matches.

Attributes Summary

usesMatches

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.
makeSubtask(name, **keyArgs) Create a subtask as a new instance as the name attribute of this task.
run(sourceCat[, sourceSelectedField, …]) Select sources and return them.
selectSources(sourceCat[, matches, exposure]) Return a bool array representing which sources to select from sourceCat.
timer(name, logLevel) Context manager to log performance data for an arbitrary block of code.

Attributes Documentation

usesMatches = False

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")
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(sourceCat, sourceSelectedField=None, matches=None, exposure=None)

Select sources and return them.

The input catalog must be contiguous in memory.

Parameters:
sourceCat : Various table formats

Catalog of sources to select from. Can be lsst.afw.table.SourceCatalog or pandas.DataFrame or astropy.table.Table,

sourceSelectedField : str or None

Name of flag field in sourceCat to set for selected sources. If set, will modify sourceCat in-place.

matches : list of lsst.afw.table.ReferenceMatch or None

List of matches to use for source selection. If usesMatches is set in source selector this field is required. If not, it is ignored.

exposure : lsst.afw.image.Exposure or None

The exposure the catalog was built from; used for debug display.

Returns:
struct : lsst.pipe.base.Struct

The struct contains the following data:

sourceCat

The catalog of sources that were selected. (may not be memory-contiguous) (lsst.afw.table.SourceCatalog or pandas.DataFrame or astropy.table.Table)

selected

Boolean array of sources that were selected, same length as sourceCat. (numpy.ndarray of bool)

Raises:
RuntimeError

Raised if sourceCat is not contiguous.

selectSources(sourceCat, matches=None, exposure=None)

Return a bool array representing which sources to select from sourceCat.

The input catalog must be contiguous in memory.

Parameters:
sourceCat : lsst.afw.table.SourceCatalog

Catalog of sources to select from.

matches : list of lsst.afw.table.ReferenceMatch or None

Ignored in this SourceSelector.

exposure : lsst.afw.image.Exposure or None

The exposure the catalog was built from; used for debug display.

Returns:
struct : lsst.pipe.base.Struct

The struct contains the following data:

selected

Boolean array of sources that were selected, same length as sourceCat. (numpy.ndarray of bool)

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