DirectMatchTask

class lsst.meas.astrom.DirectMatchTask(butler=None, refObjLoader=None, **kwargs)

Bases: lsst.pipe.base.Task

Simple, brute force matching of a source catalog to a reference catalog.

Parameters:

butler : None

Compatibility parameter. Should not be used.

refObjLoader : lsst.meas.algorithms.ReferenceObjectLoader or None

For loading reference objects.

**kwargs

Other keyword arguments required for instantiating a Task (such as config).

Methods Summary

calculateCircle(catalog)	Calculate a circle enclosing the catalog.
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(catalog[, filterName, epoch])	Load reference objects and match to them.
setRefObjLoader(refObjLoader)	Set the reference object loader for the task.
timer(name, logLevel)	Context manager to log performance data for an arbitrary block of code.

Methods Documentation

calculateCircle(catalog)

Calculate a circle enclosing the catalog.

Parameters:

catalog : lsst.afw.table.SourceCatalog

Catalog to encircle.

Returns:

result : lsst.pipe.base.Struct

Result struct with components:

center

ICRS center coordinate (lsst.afw.geom.SpherePoint).

radius

Radius of the circle (lsst.geom.Angle).

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(catalog, filterName=None, epoch=None)

Load reference objects and match to them.

Parameters:

catalog : lsst.afw.table.SourceCatalog

Catalog to match.

filterName : str

Name of filter loading fluxes.

epoch : astropy.time.Time or None

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

Returns:

result : lsst.pipe.base.Struct

Result struct with components:

matches

Matched sources with associated reference (lsst.afw.table.SourceMatchVector).

matchMeta

Match metadata (lsst.meas.astrom.MatchMetadata).

setRefObjLoader(refObjLoader)

Set the reference object loader for the task.

Parameters:

refObjLoader : lsst.meas.algorithms.ReferenceObjectLoader

An instance of a reference object loader.

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