DefineVisitsTask

class lsst.obs.base.DefineVisitsTask(config: DefineVisitsConfig, *, butler: Butler, **kwargs: Any)

Bases: Task

Driver Task for defining visits (and their spatial regions) in Gen3 Butler repositories.

Parameters:
configDefineVisitsConfig

Configuration for the task.

butlerButler

Writeable butler instance. Will be used to read raw.wcs and camera datasets and insert/sync dimension data.

**kwargs

Additional keyword arguments are forwarded to the lsst.pipe.base.Task constructor.

Notes

Each instance of DefineVisitsTask reads from / writes to the same Butler. Each invocation of DefineVisitsTask.run processes an independent group of exposures into one or more new visits, all belonging to the same visit system and instrument.

The actual work of grouping exposures and computing regions is delegated to pluggable subtasks (GroupExposuresTask and ComputeVisitRegionsTask), respectively. The defaults are to create one visit for every exposure, and to use exactly one (arbitrary) detector-level raw dataset’s WCS along with camera geometry to compute regions for all detectors. Other implementations can be created and configured for instruments for which these choices are unsuitable (e.g. because visits and exposures are not one-to-one, or because raw.wcs datasets for different detectors may not be consistent with camera geometry).

It is not necessary in general to ingest all raws for an exposure before defining a visit that includes the exposure; this depends entirely on the ComputeVisitRegionTask subclass used. For the default configuration, a single raw for each exposure is sufficient.

Defining the same visit the same way multiple times (e.g. via multiple invocations of this task on the same exposures, with the same configuration) is safe, but it may be inefficient, as most of the work must be done before new visits can be compared to existing visits.

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(dataIds, *[, collections, ...])

Add visit definitions to the registry for the given exposures.

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() 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(dataIds: Iterable[DataCoordinate | Mapping[str, Any]], *, collections: str | None = None, update_records: bool = False, incremental: bool = False) None

Add visit definitions to the registry for the given exposures.

Parameters:
dataIdsIterable [ dict or DataCoordinate ]

Exposure-level data IDs. These must all correspond to the same instrument, and are expected to be on-sky science exposures.

collectionsAny, optional

Collections to be searched for raws and camera geometry, overriding self.butler.collections. Can be any of the types supported by the collections argument to butler construction.

update_recordsbool, optional

If True (False is default), update existing visit records that conflict with the new ones instead of rejecting them (and when this occurs, update visit_detector_region as well). THIS IS AN ADVANCED OPTION THAT SHOULD ONLY BE USED TO FIX REGIONS AND/OR METADATA THAT ARE KNOWN TO BE BAD, AND IT CANNOT BE USED TO REMOVE EXPOSURES OR DETECTORS FROM A VISIT.

incrementalbool, optional

If True indicate that exposures are being ingested incrementally and visit definition will be run on partial visits. This will force update_records to True. If there is any risk that files are being ingested incrementally it is critical that this parameter is set to True and not to rely on updated_records.

Raises:
lsst.daf.butler.registry.ConflictingDefinitionError

Raised if a visit ID conflict is detected and the existing visit differs from the new one.

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.

See also

lsst.utils.timer.logInfo

Implementation function.

Examples

Creating a timer context:

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