DiaCatalogSourceSelectorTask

class lsst.ip.diffim.DiaCatalogSourceSelectorTask(**kwargs)

Bases: lsst.meas.algorithms.sourceSelector.BaseSourceSelectorTask

A task that selects sources for Kernel candidates.

A naive star selector based on second moments. Use with caution.

Notes

Debug Variables

DiaCatalogSourceSelectorTask has a debug dictionary with the following keys:

displaybool

if True display debug information

displayExposurebool

if True display exposure

pauseAtEnd bool

if True wait after displaying everything and wait for user input

Examples

For example, put something like:

import lsstDebug
def DebugInfo(name):
    di = lsstDebug.getInfo(name)  # N.b. lsstDebug.Info(name) would call us recursively
    if name.endswith("diaCatalogSourceSelector"):
        di.display = True

    return di

lsstDebug.Info = DebugInfo

into your debug.py file and run your task with the --debug flag.

Attributes Summary

usesMatches

Methods Summary

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.
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(sourceCat[, sourceSelectedField, …])	Select sources and return them.
selectSources(sourceCat[, matches, exposure])	Return a selection of sources for Kernel candidates.
timer(name[, logLevel])	Context manager to log performance data for an arbitrary block of code.

Attributes Documentation

usesMatches = True

Methods Documentation

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

schemacatalogsdict

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

metadatalsst.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

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()

Get the name of the task.

Returns

taskNamestr

Name of the task.

See also

getFullName

getSchemaCatalogs()

Get the schemas generated by this task.

Returns

schemaCatalogsdict

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 implemenation 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

taskDictdict

Dictionary containing full task name: task object for the top-level task and all subtasks, sub-subtasks, etc..

classmethod makeField(doc)

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("a brief description of what this task does")

makeSubtask(name, **keyArgs)

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 pex_config ConfigurableField or RegistryField.

run(sourceCat, sourceSelectedField=None, matches=None, exposure=None)

Select sources and return them.

The input catalog must be contiguous in memory.

Raises

RuntimeError

Raised if sourceCat is not contiguous.

selectSources(sourceCat, matches=None, exposure=None)

Return a selection of sources for Kernel candidates.

Parameters

sourceCatlsst.afw.table.SourceCatalog

Catalog of sources to select from. This catalog must be contiguous in memory.

matcheslist of lsst.afw.table.ReferenceMatch

A match vector as produced by meas_astrom.

exposurelsst.afw.image.Exposure or None

The exposure the catalog was built from; used for debug display.

Returns

structlsst.pipe.base.Struct

The struct contains the following data:

• selectedarray of bool`

  Boolean array of sources that were selected, same length as sourceCat.

timer(name, logLevel=10000)

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.

logLevel

A lsst.log level constant.

See also

timer.logInfo

Examples

Creating a timer context:

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