SingleFrameMeasurementTask¶

class lsst.meas.base.SingleFrameMeasurementTask(schema, algMetadata=None, **kwds)¶

Bases: lsst.meas.base.BaseMeasurementTask

A subtask for measuring the properties of sources on a single exposure.

Parameters:

schema : lsst.afw.table.Schema: Schema of the output resultant catalog. Will be updated to provide fields to accept the outputs of plugins which will be executed by this task.
algMetadata : lsst.daf.base.PropertyList, optional: Used to record metadaa about algorithm execution. An empty lsst.daf.base.PropertyList will be created if None.
**kwds: Keyword arguments forwarded to BaseMeasurementTask.

Attributes Summary

`NOISE_EXPOSURE_ID`	Name by which the noise exposire ID is recorded in metadata (‘str’).
`NOISE_OFFSET`	Name by which the noise offset is recorded in metadata (‘str’).
`NOISE_SEED_MULTIPLIER`	Name by which the noise seed multiplier is recorded in metadata (‘str’).
`NOISE_SOURCE`	Name by which the noise source is recorded in metadata (‘str’).
`algMetadata`
`plugins`

Methods Summary

`callMeasure`(measRecord, args, *kwds)	Call `measure` on all plugins and consistently handle exceptions.
`callMeasureN`(measCat, args, *kwds)	Call `measureN` on all plugins and consistently handle exceptions.
`doMeasurement`(plugin, measRecord, args, *kwds)	Call `measure` on the specified plugin.
`doMeasurementN`(plugin, measCat, args, *kwds)	Call `measureN` on the specified plugin.
`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.
`initializePlugins`(**kwds)	Initialize plugins (and slots) according to configuration.
`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.
`measure`(measCat, exposure)	Backwards-compatibility alias for `run`.
`run`(measCat, exposure[, noiseImage, …])	Run single frame measurement over an exposure and source catalog.
`runPlugins`(noiseReplacer, measCat, exposure)	Call the configured measument plugins on an image.
`timer`(name[, logLevel])	Context manager to log performance data for an arbitrary block of code.

Attributes Documentation

NOISE_EXPOSURE_ID = 'NOISE_EXPOSURE_ID'¶: Name by which the noise exposire ID is recorded in metadata (‘str’).

NOISE_OFFSET = 'NOISE_OFFSET'¶: Name by which the noise offset is recorded in metadata (‘str’).

NOISE_SEED_MULTIPLIER = 'NOISE_SEED_MULTIPLIER'¶: Name by which the noise seed multiplier is recorded in metadata (‘str’).

NOISE_SOURCE = 'NOISE_SOURCE'¶: Name by which the noise source is recorded in metadata (‘str’).

algMetadata = None¶

plugins = None¶

Methods Documentation

callMeasure(measRecord, *args, **kwds)¶

Call measure on all plugins and consistently handle exceptions.

Parameters:

measRecord : lsst.afw.table.SourceRecord

The record corresponding to the object being measured. Will be updated in-place with the results of measurement.

*args

Positional arguments forwarded to plugin.measure

**kwds

Keyword arguments. Two are handled locally:

beginOrder : int: Beginning execution order (inclusive). Measurements with executionOrder < beginOrder are not executed. None for no limit.
endOrder : int: Ending execution order (exclusive). Measurements with executionOrder >= endOrder are not executed. None for no limit.

Others are forwarded to plugin.measure().

Notes

This method can be used with plugins that have different signatures; the only requirement is that measRecord be the first argument. Subsequent positional arguments and keyword arguments are forwarded directly to the plugin.

This method should be considered “protected”: it is intended for use by derived classes, not users.

callMeasureN(measCat, *args, **kwds)¶

Call measureN on all plugins and consistently handle exceptions.

Parameters:

measCat : lsst.afw.table.SourceCatalog

Catalog containing only the records for the source family to be measured, and where outputs should be written.

*args

Positional arguments forwarded to plugin.measure()

**kwds

Keyword arguments. Two are handled locally:

beginOrder:: Beginning execution order (inclusive): Measurements with executionOrder < beginOrder are not executed. None for no limit.
endOrder:: Ending execution order (exclusive): measurements with executionOrder >= endOrder are not executed. None for no limit.

Others are are forwarded to plugin.measure().

Notes

This method can be used with plugins that have different signatures; the only requirement is that measRecord be the first argument. Subsequent positional arguments and keyword arguments are forwarded directly to the plugin.

This method should be considered “protected”: it is intended for use by derived classes, not users.

doMeasurement(plugin, measRecord, *args, **kwds)¶

Call measure on the specified plugin.

Exceptions are handled in a consistent way.

Parameters:	plugin : subclass of `BasePlugin` Plugin that will be executed. measRecord : `lsst.afw.table.SourceRecord` The record corresponding to the object being measured. Will be updated in-place with the results of measurement. args Positional arguments forwarded to `plugin.measure()`. *kwds Keyword arguments forwarded to `plugin.measure()`.

Notes

This method can be used with plugins that have different signatures; the only requirement is that plugin and measRecord be the first two arguments. Subsequent positional arguments and keyword arguments are forwarded directly to the plugin.

This method should be considered “protected”: it is intended for use by derived classes, not users.

doMeasurementN(plugin, measCat, *args, **kwds)¶

Call measureN on the specified plugin.

Exceptions are handled in a consistent way.

Parameters:	plugin : subclass of `BasePlugin` Plugin that will be executed. measCat : `lsst.afw.table.SourceCatalog` Catalog containing only the records for the source family to be measured, and where outputs should be written. args Positional arguments forwarded to `plugin.measureN()`. *kwds Keyword arguments forwarded to `plugin.measureN()`.

Notes

This method can be used with plugins that have different signatures; the only requirement is that the plugin and measCat be the first two arguments. Subsequent positional arguments and keyword arguments are forwarded directly to the plugin.

This method should be considered “protected”: it is intended for use by derived classes, not users.

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 : `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()¶

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

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.

initializePlugins(**kwds)¶

Initialize plugins (and slots) according to configuration.

Parameters:	**kwds Keyword arguments forwarded directly to plugin constructors.

Notes

Derived class constructors should call this method to fill the plugins attribute and add corresponding output fields and slot aliases to the output schema.

In addition to the attributes added by BaseMeasurementTask.__init__, a schema` attribute holding the output schema must be present before this method is called.

Keyword arguments are forwarded directly to plugin constructors, allowing derived classes to use plugins with different signatures.

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")

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.

measure(measCat, exposure)¶: Backwards-compatibility alias for run.

run(measCat, exposure, noiseImage=None, exposureId=None, beginOrder=None, endOrder=None)¶

Run single frame measurement over an exposure and source catalog.

Parameters:

measCat : lsst.afw.table.SourceCatalog: Catalog to be filled with the results of measurement. Must contain all the lsst.afw.table.SourceRecords to be measured (with lsst.afw.detection.Footprints attached), and have a schema that is a superset of self.schema.
exposure : lsst.afw.image.ExposureF: Image containing the pixel data to be measured together with associated PSF, WCS, etc.
noiseImage : lsst.afw.image.ImageF, optional: Can be used to specify the a predictable noise replacement field for testing purposes.
exposureId : int, optional: Unique exposure identifier used to calculate the random number generator seed during noise replacement.
beginOrder : float, optional: Start execution order (inclusive): measurements with executionOrder < beginOrder are not executed. None for no limit.
endOrder : float, optional: Final execution order (exclusive): measurements with executionOrder >= endOrder are not executed. None for no limit.

runPlugins(noiseReplacer, measCat, exposure, beginOrder=None, endOrder=None)¶

Call the configured measument plugins on an image.

Parameters:

noiseReplacer : NoiseReplacer: Used to fill sources not being measured with noise.
measCat : lsst.afw.table.SourceCatalog: Catalog to be filled with the results of measurement. Must contain all the lsst.afw.table.SourceRecords to be measured (with lsst.afw.detection.Footprints attached), and have a schema that is a superset of self.schema.
exposure : lsst.afw.image.ExposureF: Image containing the pixel data to be measured together with associated PSF, WCS, etc.
beginOrder : float, optional: Start execution order (inclusive): measurements with executionOrder < beginOrder are not executed. None for no limit.
endOrder : float, optional: Final execution order (exclusive): measurements with executionOrder >= endOrder are not executed. None for no limit.

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.

Navigation

SingleFrameMeasurementTask¶