SourceDeblendTask

class lsst.meas.deblender.SourceDeblendTask(schema, peakSchema=None, **kwargs)

Bases: lsst.pipe.base.Task

Split blended sources into individual sources.

This task has no return value; it only modifies the SourceCatalog in-place.

Methods Summary

addSchemaKeys(schema)
deblend(exposure, srcs, psf) Deblend.
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.
isLargeFootprint(footprint) Returns whether a Footprint is large
isMasked(footprint, mask) Returns whether the footprint violates the mask limits
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.
postSingleDeblendHook(exposure, srcs, i, …)
preSingleDeblendHook(exposure, srcs, i, fp, …)
run(exposure, sources) Get the PSF from the provided exposure and then run deblend.
skipParent(source, mask) Indicate that the parent source is not being deblended
timer(name, logLevel) Context manager to log performance data for an arbitrary block of code.

Methods Documentation

addSchemaKeys(schema)
deblend(exposure, srcs, psf)

Deblend.

Parameters:
exposure : lsst.afw.image.Exposure

Exposure to be processed

srcs : lsst.afw.table.SourceCatalog

SourceCatalog containing sources detected on this exposure

psf : lsst.afw.detection.Psf

Point source function

Returns:
None
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.

isLargeFootprint(footprint)

Returns whether a Footprint is large

‘Large’ is defined by thresholds on the area, size and axis ratio. These may be disabled independently by configuring them to be non-positive.

This is principally intended to get rid of satellite streaks, which the deblender or other downstream processing can have trouble dealing with (e.g., multiple large HeavyFootprints can chew up memory).

isMasked(footprint, mask)

Returns whether the footprint violates the mask limits

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.

postSingleDeblendHook(exposure, srcs, i, npre, kids, fp, psf, psf_fwhm, sigma1, res)
preSingleDeblendHook(exposure, srcs, i, fp, psf, psf_fwhm, sigma1)
run(exposure, sources)

Get the PSF from the provided exposure and then run deblend.

Parameters:
exposure : lsst.afw.image.Exposure

Exposure to be processed

sources : lsst.afw.table.SourceCatalog

SourceCatalog containing sources detected on this exposure.

skipParent(source, mask)

Indicate that the parent source is not being deblended

We set the appropriate flags and mask.

Parameters:
source : lsst.afw.table.SourceRecord

The source to flag as skipped

mask : lsst.afw.image.Mask

The mask to update

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