LoadReferenceCatalogTask

class lsst.pipe.tasks.loadReferenceCatalog.LoadReferenceCatalogTask(*, dataIds, refCats, name, **kwargs)

Bases: lsst.pipe.base.Task

Load multi-band reference objects from a reference catalog.

Parameters:

dataIds : iterable of lsst.daf.butler.dataId

An iterable object of dataIds which point to reference catalogs in a Gen3 repository. Required for Gen3.

refCats : iterable of lsst.daf.butler.DeferredDatasetHandle

An iterable object of dataset refs for reference catalogs in a Gen3 repository.

name : str

The name of the refcat that this object will load. This name is used for applying colorterms, for example.

Raises:

RuntimeError if dataIds or refCats is None.

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.
getPixelBoxCatalog(bbox, wcs, filterList[, …])	Get a multi-band reference catalog by specifying a bounding box and WCS.
getSkyCircleCatalog(center, radius, filterList)	Get a multi-band reference catalog by specifying a center and radius.
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.

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

getPixelBoxCatalog(bbox, wcs, filterList, epoch=None, bboxToSpherePadding=None)

Get a multi-band reference catalog by specifying a bounding box and WCS.

The catalog will be in numpy.ndarray, with positions proper-motion corrected to “epoch” (if specified, and if the reference catalog has proper motions); sources cut on a reference selector (if “config.doReferenceSelection = True”); and color-terms applied (if “config.doApplyColorTerms = True”).

The format of the reference catalog will be of the format:

dtype = [(‘ra’, ‘np.float64’),

(‘dec’, ‘np.float64’), (‘refMag’, ‘np.float32’, (len(filterList), )), (‘refMagErr’, ‘np.float32’, (len(filterList), ))]

Reference magnitudes (AB) and errors will be 99 for non-detections in a given band.

Parameters:

bbox : lsst.geom.Box2I

Box which bounds a region in pixel space.

wcs : lsst.afw.geom.SkyWcs

Wcs object defining the pixel to sky (and reverse) transform for the supplied bbox.

filterList : List [ str ]

List of camera physicalFilter names to retrieve magnitudes.

epoch : astropy.time.Time, optional

Epoch to which to correct proper motion and parallax (if available), or None to not apply such corrections.

bboxToSpherePadding : int, optional

Padding to account for translating a set of corners into a spherical (convex) boundary that is certain to encompass the entire area covered by the bbox.

Returns:

refCat : numpy.ndarray

Reference catalog.

getSkyCircleCatalog(center, radius, filterList, epoch=None, catalogFormat='numpy')

Get a multi-band reference catalog by specifying a center and radius.

The catalog will be in numpy.ndarray, with positions proper-motion corrected to “epoch” (if specified, and if the reference catalog has proper motions); sources cut on a reference selector (if “config.doReferenceSelection = True”); and color-terms applied (if “config.doApplyColorTerms = True”).

The format of the reference catalog will be of the format:

dtype = [(‘ra’, ‘np.float64’),

(‘dec’, ‘np.float64’), (‘refMag’, ‘np.float32’, (len(filterList), )), (‘refMagErr’, ‘np.float32’, (len(filterList), ))]

Reference magnitudes (AB) and errors will be 99 for non-detections in a given band.

Parameters:

center : lsst.geom.SpherePoint

Point defining the center of the circular region.

radius : lsst.geom.Angle

Defines the angular radius of the circular region.

filterList : List [ str ]

List of camera physicalFilter names to retrieve magnitudes.

epoch : astropy.time.Time, optional

Epoch to which to correct proper motion and parallax (if available), or None to not apply such corrections.

Returns:

refCat : numpy.ndarray

Reference catalog.

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.

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