GroupExposuresTask

class lsst.obs.base.GroupExposuresTask(config: GroupExposuresConfig, **kwargs: Any)

Bases: Task

Abstract base class for the subtask of DefineVisitsTask that is responsible for grouping exposures into visits.

Subclasses should be registered with GroupExposuresTask.registry to enable use by DefineVisitsTask, and should generally correspond to a particular ‘visit_system’ dimension value. They are also responsible for defining visit IDs and names that are unique across all visit systems in use by an instrument.

Parameters:

configGroupExposuresConfig

Configuration information.

**kwargs

Additional keyword arguments forwarded to the Task constructor.

Attributes Summary

registry

Methods Summary

emptyMetadata()	Empty (clear) the metadata for this Task and all sub-Tasks.
find_missing(exposures, registry)	Determine, if possible, which exposures might be missing.
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.
getVisitSystems()	Return identifiers for the 'visit_system' dimension this algorithm implements.
group(exposures)	Group the given exposures into visits.
group_exposures(exposures)	Group the exposures in a way most natural for this visit definition.
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.

Attributes Documentation

registry = <abc.Registry object>

Methods Documentation

emptyMetadata() → None

Empty (clear) the metadata for this Task and all sub-Tasks.

abstract find_missing(exposures: list[lsst.daf.butler.core.dimensions._records.DimensionRecord], registry: Registry) → list[lsst.daf.butler.core.dimensions._records.DimensionRecord]

Determine, if possible, which exposures might be missing.

Parameters:

exposureslist of lsst.daf.butler.DimensionRecord

The exposure records to analyze.

registrylsst.daf.butler.Registry

A butler registry that contains these exposure records.

Returns:

missinglist of lsst.daf.butler.DimensionRecord

Any exposure records present in registry that were related to the given exposures but were missing from that list and deemed to be relevant.

Notes

Only some grouping schemes are able to find missing exposures. It is acceptable to return an empty list.

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

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.

getVisitSystems() → set[lsst.obs.base.defineVisits.VisitSystem]

Return identifiers for the ‘visit_system’ dimension this algorithm implements.

Returns:

visit_systemsSet [VisitSystem]

The visit systems used by this algorithm.

abstract group(exposures: list[lsst.daf.butler.core.dimensions._records.DimensionRecord]) → Iterable[VisitDefinitionData]

Group the given exposures into visits.

Parameters:

exposureslist [ DimensionRecord ]

DimensionRecords (for the ‘exposure’ dimension) describing the exposures to group.

Returns:

visitsIterable [ VisitDefinitionData ]

Structs identifying the visits and the exposures associated with them. This may be an iterator or a container.

abstract group_exposures(exposures: list[lsst.daf.butler.core.dimensions._records.DimensionRecord]) → dict[Any, list[lsst.daf.butler.core.dimensions._records.DimensionRecord]]

Group the exposures in a way most natural for this visit definition.

Parameters:

exposureslist of lsst.daf.butler.DimensionRecord

The exposure records to group.

Returns:

groupsdict [Any, list of DimensionRecord]

Groupings of exposure records. The key type is relevant to the specific visit definition and could be a string or a tuple.

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.

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.

logLevel

A logging level constant.

See also

lsst.utils.timer.logInfo

Examples

Creating a timer context:

with self.timer("someCodeToTime"):
    pass  # code to time