MergeDetectionsTask¶
- class lsst.pipe.tasks.mergeDetections.MergeDetectionsTask(schema=None, initInputs=None, **kwargs)¶
Bases:
PipelineTask
Merge sources detected in coadds of exposures obtained with different filters.
Merge sources detected in coadds of exposures obtained with different filters. To perform photometry consistently across coadds in multiple filter bands, we create a master catalog of sources from all bands by merging the sources (peaks & footprints) detected in each coadd, while keeping track of which band each source originates in. The catalog merge is performed by
getMergedSourceCatalog
. Spurious peaks detected around bright objects are culled as described inCullPeaksConfig
.MergeDetectionsTask is meant to be run after detecting sources in coadds generated for the chosen subset of the available bands. The purpose of the task is to merge sources (peaks & footprints) detected in the coadds generated from the chosen subset of filters. Subsequent tasks in the multi-band processing procedure will deblend the generated master list of sources and, eventually, perform forced photometry.
- Parameters:
- schema
lsst.afw.table.Schema
, optional The schema of the detection catalogs used as input to this task.
- initInputs
dict
, optional Dictionary that can contain a key
schema
containing the input schema. If present will override the value ofschema
.- **kwargs
Additional keyword arguments.
- schema
Attributes Summary
Methods Summary
cullPeaks
(catalog)Attempt to remove garbage peaks (mostly on the outskirts of large blends).
Empty (clear) the metadata for this Task and all sub-Tasks.
Get metadata for all tasks.
Get the task name as a hierarchical name including parent task names.
getName
()Get the name of the task.
getSkySourceFootprints
(mergedList, skyInfo, seed)Return a list of Footprints of sky objects which don't overlap with anything in mergedList.
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
(catalogs, skyInfo, idFactory, skySeed)Merge multiple catalogs.
runQuantum
(butlerQC, inputRefs, outputRefs)Do butler IO and transform to provide in memory objects for tasks
run
method.timer
(name[, logLevel])Context manager to log performance data for an arbitrary block of code.
Attributes Documentation
Methods Documentation
- cullPeaks(catalog)¶
Attempt to remove garbage peaks (mostly on the outskirts of large blends).
- Parameters:
- catalog
lsst.afw.table.SourceCatalog
Source catalog.
- catalog
- getFullMetadata() 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.
- metadata
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”.
- fullName
- getName() str ¶
Get the name of the task.
- Returns:
- taskName
str
Name of the task.
- taskName
See also
getFullName
Get the full name of the task.
- getSkySourceFootprints(mergedList, skyInfo, seed)¶
Return a list of Footprints of sky objects which don’t overlap with anything in mergedList.
- Parameters:
- mergedList
lsst.afw.table.SourceCatalog
The merged Footprints from all the input bands.
- skyInfo
lsst.pipe.base.Struct
A description of the patch.
- seed
int
Seed for the random number generator.
- mergedList
- 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.
- taskDict
- classmethod makeField(doc: str) ConfigurableField ¶
Make a
lsst.pex.config.ConfigurableField
for this task.- Parameters:
- doc
str
Help text for the field.
- doc
- Returns:
- configurableField
lsst.pex.config.ConfigurableField
A
ConfigurableField
for this task.
- configurableField
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:
- 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
.
- name
Notes
The subtask must be defined by
Task.config.name
, an instance ofConfigurableField
orRegistryField
.
- run(catalogs, skyInfo, idFactory, skySeed)¶
Merge multiple catalogs.
After ordering the catalogs and filters in priority order,
getMergedSourceCatalog
of theFootprintMergeList
created by__init__
is used to perform the actual merging. Finally,cullPeaks
is used to remove garbage peaks detected around bright objects.- Parameters:
- catalogs
lsst.afw.table.SourceCatalog
Catalogs to be merged.
- mergedList
lsst.afw.table.SourceCatalog
Merged catalogs.
- catalogs
- Returns:
- result
lsst.pipe.base.Struct
Results as a struct with attributes:
outputCatalog
Merged catalogs (
lsst.afw.table.SourceCatalog
).
- result
- runQuantum(butlerQC, inputRefs, outputRefs)¶
Do butler IO and transform to provide in memory objects for tasks
run
method.- Parameters:
- butlerQC
QuantumContext
A butler which is specialized to operate in the context of a
lsst.daf.butler.Quantum
.- inputRefs
InputQuantizedConnection
Datastructure whose attribute names are the names that identify connections defined in corresponding
PipelineTaskConnections
class. The values of these attributes are thelsst.daf.butler.DatasetRef
objects associated with the defined input/prerequisite connections.- outputRefs
OutputQuantizedConnection
Datastructure whose attribute names are the names that identify connections defined in corresponding
PipelineTaskConnections
class. The values of these attributes are thelsst.daf.butler.DatasetRef
objects associated with the defined output connections.
- butlerQC