BaseSourceSelectorTask¶

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

Bases: lsst.pipe.base.Task

Base class for source selectors

Source selectors are classes that perform a selection on a catalog object given a set of criteria or cuts. They return the selected catalog and can optionally set a specified Flag field in the input catalog to identify if the source was selected.

Register all source selectors with the sourceSelectorRegistry using:: sourceSelectorRegistry.register(name, class)

Attributes:	usesMatches : `bool` A boolean variable specify if the inherited source selector uses matches to an external catalog, and thus requires the `matches` argument to `run()`.

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 some 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() → 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 selection of sources selected by some criteria.

Parameters:

sourceCat : Various table formats: Catalog of sources to select from. Supports lsst.afw.table.SourceCatalog or pandas.DataFrame or astropy.table.Table This catalog must be contiguous in memory.
matches : list of lsst.afw.table.ReferenceMatch or None: A list of lsst.afw.table.ReferenceMatch objects
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.

Navigation

BaseSourceSelectorTask¶