ScienceSourceSelectorTask¶

class lsst.meas.algorithms.ScienceSourceSelectorTask(**kwargs)¶

Bases: BaseSourceSelectorTask

Science source selector

By “science” sources, we mean sources that are on images that we are processing, as opposed to sources from reference catalogs.

This selects (science) sources by (optionally) applying each of a magnitude limit, flag requirements and star/galaxy separation.

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 selection of sources selected by specified criteria.
`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() → 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.

run(sourceCat, sourceSelectedField=None, matches=None, exposure=None)¶

Select sources and return them.

The input catalog must be contiguous in memory.

Parameters:

sourceCatVarious table formats: Catalog of sources to select from. Can be lsst.afw.table.SourceCatalog or pandas.DataFrame or astropy.table.Table,
sourceSelectedFieldstr or None: Name of flag field in sourceCat to set for selected sources. If set, will modify sourceCat in-place.
matcheslist 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.
exposurelsst.afw.image.Exposure or None: The exposure the catalog was built from; used for debug display.

Returns:

structlsst.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 selection of sources selected by specified criteria.

Parameters:

sourceCatlsst.afw.table.SourceCatalog: Catalog of sources to select from. This catalog must be contiguous in memory.
matcheslist of lsst.afw.table.ReferenceMatch or None: Ignored in this SourceSelector.
exposurelsst.afw.image.Exposure or None: The exposure the catalog was built from; used for debug display.

Returns:

structlsst.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:

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

Navigation

ScienceSourceSelectorTask¶