PackageAlertsTask

class lsst.ap.association.PackageAlertsTask(**kwargs)

Bases: lsst.pipe.base.Task

Tasks for packaging Dia and Pipelines data into Avro alert packages.

Methods Summary

createCcdDataCutout(image, skyCenter, …)	Grab an image as a cutout and return a calibrated CCDData image.
createDiaSourceExtent(bboxSize)	Create a extent for a box for the cutouts given the size of the square BBox that covers the source footprint.
emptyMetadata()	Empty (clear) the metadata for this Task and all sub-Tasks.
getAllSchemaCatalogs()	Get schema catalogs for all tasks in the hierarchy, combining the results into a single dict.
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.
getSchemaCatalogs()	Get the schemas generated by this task.
getTaskDict()	Get a dictionary of all tasks as a shallow copy.
makeAlertDict(alertId, diaSource, diaObject, …)	Convert data and package into a dictionary alert.
makeField(doc)	Make a lsst.pex.config.ConfigurableField for this task.
makeLocalTransformMatrix(wcs, center, skyCenter)	Create a local, linear approximation of the wcs transformation matrix.
makeSubtask(name, **keyArgs)	Create a subtask as a new instance as the name attribute of this task.
run(diaSourceCat, diaObjectCat, …)	Package DiaSources/Object and exposure data into Avro alerts.
streamCcdDataToBytes(cutout)	Serialize a cutout into bytes.
timer(name[, logLevel])	Context manager to log performance data for an arbitrary block of code.

Methods Documentation

createCcdDataCutout(image, skyCenter, extent, photoCalib, srcId)

Grab an image as a cutout and return a calibrated CCDData image.

Parameters:

image : lsst.afw.image.ExposureF

Image to pull cutout from.

skyCenter : lsst.geom.SpherePoint

Center point of DiaSource on the sky.

extent : lsst.geom.Extent2I

Bounding box to cutout from the image.

photoCalib : lsst.afw.image.PhotoCalib

Calibrate object of the image the cutout is cut from.

srcId : int

Unique id of DiaSource. Used for when an error occurs extracting a cutout.

Returns:

ccdData : astropy.nddata.CCDData or None

CCDData object storing the calibrate information from the input difference or template image.

createDiaSourceExtent(bboxSize)

Create a extent for a box for the cutouts given the size of the square BBox that covers the source footprint.

Parameters:

bboxSize : int

Size of a side of the square bounding box in pixels.

Returns:

extent : lsst.geom.Extent2I

Geom object representing the size of the bounding box.

emptyMetadata()

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

getAllSchemaCatalogs()

Get schema catalogs for all tasks in the hierarchy, combining the results into a single dict.

Returns:

schemacatalogs : dict

Keys are butler dataset type, values are a empty catalog (an instance of the appropriate lsst.afw.table Catalog type) for all tasks in the hierarchy, from the top-level task down through all subtasks.

Notes

This method may be called on any task in the hierarchy; it will return the same answer, regardless.

The default implementation should always suffice. If your subtask uses schemas the override Task.getSchemaCatalogs, not this method.

getFullMetadata()

Get metadata for all tasks.

Returns:

metadata : lsst.daf.base.PropertySet

The PropertySet 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()

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()

Get the name of the task.

Returns:

taskName : str

Name of the task.

See also

getFullName

getSchemaCatalogs()

Get the schemas generated by this task.

Returns:

schemaCatalogs : dict

Keys are butler dataset type, values are an empty catalog (an instance of the appropriate lsst.afw.table Catalog type) for this task.

See also

Task.getAllSchemaCatalogs

Notes

Warning

Subclasses that use schemas must override this method. The default implementation returns an empty dict.

This method may be called at any time after the Task is constructed, which means that all task schemas should be computed at construction time, not when data is actually processed. This reflects the philosophy that the schema should not depend on the data.

Returning catalogs rather than just schemas allows us to save e.g. slots for SourceCatalog as well.

getTaskDict()

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.

makeAlertDict(alertId, diaSource, diaObject, objDiaSrcHistory, objDiaForcedSources, diffImCutout, templateCutout)

Convert data and package into a dictionary alert.

Parameters:

diaSource : pandas.DataFrame

New single DiaSource to package.

diaObject : pandas.DataFrame

DiaObject that diaSource is matched to.

objDiaSrcHistory : pandas.DataFrame

12 month history of diaObject excluding the latest DiaSource.

objDiaForcedSources : pandas.DataFrame

12 month history of diaObject forced measurements.

diffImCutout : astropy.nddata.CCDData or None

Cutout of the difference image around the location of diaSource with a min size set by the cutoutSize configurable.

templateCutout : astropy.nddata.CCDData or None

Cutout of the template image around the location of diaSource with a min size set by the cutoutSize configurable.

classmethod makeField(doc)

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")

makeLocalTransformMatrix(wcs, center, skyCenter)

Create a local, linear approximation of the wcs transformation matrix.

The approximation is created as if the center is at RA=0, DEC=0. All comparing x,y coordinate are relative to the position of center. Matrix is initially calculated with units arcseconds and then converted to degrees. This yields higher precision results due to quirks in AST.

Parameters:

wcs : lsst.afw.geom.SkyWcs

Wcs to approximate

center : lsst.geom.Point2D

Point at which to evaluate the LocalWcs.

skyCenter : lsst.geom.SpherePoint

Point on sky to approximate the Wcs.

Returns:

localMatrix : numpy.ndarray

Matrix representation the local wcs approximation with units degrees.

makeSubtask(name, **keyArgs)

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.

run(diaSourceCat, diaObjectCat, diaSrcHistory, diaForcedSources, diffIm, template, ccdExposureIdBits)

Package DiaSources/Object and exposure data into Avro alerts.

Writes Avro alerts to a location determined by the alertWriteLocation configurable.

Parameters:

diaSourceCat : pandas.DataFrame

New DiaSources to package. DataFrame should be indexed on ["diaObjectId", "filterName", "diaSourceId"]

diaObjectCat : pandas.DataFrame

New and updated DiaObjects matched to the new DiaSources. DataFrame is indexed on ["diaObjectId"]

diaSrcHistory : pandas.DataFrame

12 month history of DiaSources matched to the DiaObjects. Excludes the newest DiaSource and is indexed on ["diaObjectId", "filterName", "diaSourceId"]

diaForcedSources : pandas.DataFrame

12 month history of DiaForcedSources matched to the DiaObjects. ["diaObjectId"]

diffIm : lsst.afw.image.ExposureF

Difference image the sources in diaSourceCat were detected in.

template : lsst.afw.image.ExposureF or None

Template image used to create the diffIm.

ccdExposureIdBits : int

Number of bits used in the ccdVisitId.

streamCcdDataToBytes(cutout)

Serialize a cutout into bytes.

Parameters:

cutout : astropy.nddata.CCDData

Cutout to serialize.

Returns:

coutputBytes : bytes

Input cutout serialized into byte data.

timer(name, logLevel=10)

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