DipoleMeasurementTask¶

class lsst.ip.diffim.DipoleMeasurementTask(schema, algMetadata=None, **kwds)¶

Bases: lsst.meas.base.SingleFrameMeasurementTask

@brief Measurement of Sources, specifically ones from difference images, for characterization as dipoles

@section ip_diffim_dipolemeas_Contents Contents

@ref ip_diffim_dipolemeas_Purpose

@ref ip_diffim_dipolemeas_Initialize

@ref ip_diffim_dipolemeas_IO

@ref ip_diffim_dipolemeas_Config

@ref ip_diffim_dipolemeas_Metadata

@ref ip_diffim_dipolemeas_Debug

@ref ip_diffim_dipolemeas_Example

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@section ip_diffim_dipolemeas_Purpose Description

This class provides a default configuration for running Source measurement on image differences.

These default plugins include: @dontinclude dipoleMeasurement.py @skip class DipoleMeasurementConfig @until self.doReplaceWithNoise

These plugins enabled by default allow the user to test the hypothesis that the Source is a dipole. This includes a set of measurements derived from intermediate base classes DipoleCentroidAlgorithm and DipoleFluxAlgorithm. Their respective algorithm control classes are defined in DipoleCentroidControl and DipoleFluxControl. Each centroid and flux measurement will have _neg (negative) and _pos (positive lobe) fields.

The first set of measurements uses a “naive” alrogithm for centroid and flux measurements, implemented in NaiveDipoleCentroidControl and NaiveDipoleFluxControl. The algorithm uses a naive 3x3 weighted moment around the nominal centroids of each peak in the Source Footprint. These algorithms fill the table fields ip_diffim_NaiveDipoleCentroid* and ip_diffim_NaiveDipoleFlux*

The second set of measurements undertakes a joint-Psf model on the negative and positive lobe simultaneously. This fit simultaneously solves for the negative and positive lobe centroids and fluxes using non-linear least squares minimization. The fields are stored in table elements ip_diffim_PsfDipoleFlux*.

Because this Task is just a config for SourceMeasurementTask, the same result may be acheived by manually editing the config and running SourceMeasurementTask. For example:

@code config = SingleFrameMeasurementConfig() config.plugins.names = [“base_PsfFlux”,

“ip_diffim_PsfDipoleFlux”, “ip_diffim_NaiveDipoleFlux”, “ip_diffim_NaiveDipoleCentroid”, “ip_diffim_ClassificationDipole”, “base_CircularApertureFlux”, “base_SkyCoord”]

config.slots.calibFlux = None config.slots.modelFlux = None config.slots.gaussianFlux = None config.slots.shape = None config.slots.centroid = “ip_diffim_NaiveDipoleCentroid” config.doReplaceWithNoise = False

schema = afwTable.SourceTable.makeMinimalSchema() task = SingleFrameMeasurementTask(schema, config=config)

task.run(sources, exposure) @endcode

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@section ip_diffim_dipolemeas_Initialize Task initialization

@copydoc __init__

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@section ip_diffim_dipolemeas_IO Invoking the Task

@copydoc run

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@section ip_diffim_dipolemeas_Config Configuration parameters

See @ref DipoleMeasurementConfig

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@section ip_diffim_dipolemeas_Metadata Quantities set in Metadata

No specific values are set in the Task metadata. However, the Source schema are modified to store the results of the dipole-specific measurements.

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@section ip_diffim_dipolemeas_Debug Debug variables

The @link lsst.pipe.base.cmdLineTask.CmdLineTask command line task@endlink interface supports a flag @c -d/–debug to import @b debug.py from your @c PYTHONPATH. The relevant contents of debug.py for this Task include:

@code{.py}

import sys import lsstDebug def DebugInfo(name):

di = lsstDebug.getInfo(name) if name == “lsst.ip.diffim.dipoleMeasurement”:

di.display = True # enable debug output di.maskTransparency = 90 # ds9 mask transparency di.displayDiaSources = True # show exposure with dipole results

return di

lsstDebug.Info = DebugInfo lsstDebug.frame = 1

@endcode

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@section ip_diffim_dipolemeas_Example A complete example of using DipoleMeasurementTask

This code is dipoleMeasTask.py in the examples directory, and can be run as @em e.g. @code examples/dipoleMeasTask.py examples/dipoleMeasTask.py –debug examples/dipoleMeasTask.py –debug –image /path/to/image.fits @endcode

@dontinclude dipoleMeasTask.py Start the processing by parsing the command line, where the user has the option of enabling debugging output and/or sending their own image for demonstration (in case they have not downloaded the afwdata package). @skip main @until run

@dontinclude dipoleMeasTask.py The processing occurs in the run function. We first extract an exposure from disk or afwdata, displaying it if requested: @skip args @until mtv

Create a default source schema that we will append fields to as we add more algorithms: @skip makeMinimalSchema @until makeMinimalSchema

Create the detection and measurement Tasks, with some minor tweaking of their configs: @skip Create @until measureTask

Having fully initialied the schema, we create a Source table from it: @skip output @until SourceTable

Run detection: @skip Process @until detectionTask

Because we are looking for dipoles, we need to merge the positive and negative detections: @skip Merge @until numNeg

Finally, perform measurement (both standard and dipole-specialized) on the merged sources: @skip measureTask @until measureTask

Optionally display debugging information: @skip Display @until displayDipoles #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Attributes Summary

`NOISE_EXPOSURE_ID`
`NOISE_OFFSET`
`NOISE_SEED_MULTIPLIER`
`NOISE_SOURCE`
`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.
`getPluginLogName`(pluginName)
`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'¶

NOISE_OFFSET = 'NOISE_OFFSET'¶

NOISE_SEED_MULTIPLIER = 'NOISE_SEED_MULTIPLIER'¶

NOISE_SOURCE = 'NOISE_SOURCE'¶

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 : `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

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:	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("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:	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 pex_config 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=10000)¶

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 `lsst.log` level constant.

Navigation

DipoleMeasurementTask¶