CalibrateTask

class lsst.pipe.tasks.calibrate.CalibrateTask(astromRefObjLoader=None, photoRefObjLoader=None, icSourceSchema=None, initInputs=None, **kwargs)

Bases: PipelineTask

Calibrate an exposure: measure sources and perform astrometric and photometric calibration.

Given an exposure with a good PSF model and aperture correction map(e.g. as provided by CharacterizeImageTask), perform the following operations: - Run detection and measurement - Run astrometry subtask to fit an improved WCS - Run photoCal subtask to fit the exposure’s photometric zero-point

Parameters:
butlerNone

Compatibility parameter. Should always be None.

astromRefObjLoaderlsst.meas.algorithms.ReferenceObjectLoader, optional

Unused in gen3: must be None.

photoRefObjLoaderlsst.meas.algorithms.ReferenceObjectLoader, optional

Unused in gen3: must be None.

icSourceSchemalsst.afw.table.Schema, optional

Schema for the icSource catalog.

initInputsdict, optional

Dictionary that can contain a key icSourceSchema containing the input schema. If present will override the value of icSourceSchema.

Raises:
RuntimeError

Raised if any of the following occur: - isSourceCat is missing fields specified in icSourceFieldsToCopy. - PipelineTask form of this task is initialized with reference object

loaders.

Notes

Quantities set in exposure Metadata:

MAGZERO_RMS

MAGZERO’s RMS == sigma reported by photoCal task

MAGZERO_NOBJ

Number of stars used == ngood reported by photoCal task

COLORTERM1

?? (always 0.0)

COLORTERM2

?? (always 0.0)

COLORTERM3

?? (always 0.0)

Debugging: CalibrateTask has a debug dictionary containing one key:

calibrate

frame (an int; <= 0 to not display) in which to display the exposure, sources and matches. See @ref lsst.meas.astrom.displayAstrometry for the meaning of the various symbols.

Attributes Summary

canMultiprocess

Methods Summary

copyIcSourceFields(icSourceCat, sourceCat)

Match sources in an icSourceCat and a sourceCat and copy fields.

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(exposure[, background, icSourceCat, ...])

Calibrate an exposure.

runQuantum(butlerQC, inputRefs, outputRefs)

Do butler IO and transform to provide in memory objects for tasks run method.

setMetadata(exposure[, photoRes])

Set task and exposure metadata.

timer(name[, logLevel])

Context manager to log performance data for an arbitrary block of code.

Attributes Documentation

canMultiprocess: ClassVar[bool] = True

Methods Documentation

copyIcSourceFields(icSourceCat, sourceCat)

Match sources in an icSourceCat and a sourceCat and copy fields.

The fields copied are those specified by config.icSourceFieldsToCopy.

Parameters:
icSourceCatlsst.afw.table.SourceCatalog

Catalog from which to copy fields.

sourceCatlsst.afw.table.SourceCatalog

Catalog to which to copy fields.

Raises:
RuntimeError

Raised if any of the following occur: - icSourceSchema and icSourceKeys are not specified. - icSourceCat and sourceCat are not specified. - icSourceFieldsToCopy is empty.

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(exposure, background=None, icSourceCat=None, idGenerator=None)

Calibrate an exposure.

Parameters:
exposurelsst.afw.image.ExposureF

Exposure to calibrate.

backgroundlsst.afw.math.BackgroundList, optional

Initial model of background already subtracted from exposure.

icSourceCatlsst.afw.image.SourceCatalog, optional

SourceCatalog from CharacterizeImageTask from which we can copy some fields.

idGeneratorlsst.meas.base.IdGenerator, optional

Object that generates source IDs and provides RNG seeds.

Returns:
resultlsst.pipe.base.Struct

Results as a struct with attributes:

exposure

Characterized exposure (lsst.afw.image.ExposureF).

sourceCat

Detected sources (lsst.afw.table.SourceCatalog).

outputBackground

Model of subtracted background (lsst.afw.math.BackgroundList).

astromMatches

List of source/ref matches from astrometry solver.

matchMeta

Metadata from astrometry matches.

outputExposure

Another reference to exposure for compatibility.

outputCat

Another reference to sourceCat for compatibility.

runQuantum(butlerQC, inputRefs, outputRefs)

Do butler IO and transform to provide in memory objects for tasks run method.

Parameters:
butlerQCQuantumContext

A butler which is specialized to operate in the context of a lsst.daf.butler.Quantum.

inputRefsInputQuantizedConnection

Datastructure whose attribute names are the names that identify connections defined in corresponding PipelineTaskConnections class. The values of these attributes are the lsst.daf.butler.DatasetRef objects associated with the defined input/prerequisite connections.

outputRefsOutputQuantizedConnection

Datastructure whose attribute names are the names that identify connections defined in corresponding PipelineTaskConnections class. The values of these attributes are the lsst.daf.butler.DatasetRef objects associated with the defined output connections.

setMetadata(exposure, photoRes=None)

Set task and exposure metadata.

Logs a warning continues if needed data is missing.

Parameters:
exposurelsst.afw.image.ExposureF

Exposure to set metadata on.

photoReslsst.pipe.base.Struct, optional

Result of running photoCal task.

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