CatalogCalculationPlugin

class lsst.meas.base.CatalogCalculationPlugin(config, name, schema, metadata)

Bases: BasePlugin

Base class for catalog calculation plugins.

Parameters:

configCatalogCalculationPlugin.ConfigClass

Plugin configuration.

namestr

The string the plugin was registered with.

schemalsst.afw.table.Schema

The source schema, New fields should be added here to hold output produced by this plugin.

metadatalsst.daf.base.PropertySet

Plugin metadata that will be attached to the output catalog

Attributes Summary

APCORR_ORDER	Order for algorithms which require shape, centroid and flux (float).
CENTROID_ORDER	Order for algorithms which require only Footprint and Peaks (float).
DEFAULT_CATALOGCALCULATION	Order for catalog calculation plugins.
FLUX_ORDER	Order for algorithms which require a shape and a centroid (float).
SHAPE_ORDER	Order for algorithms which require a centroid (float).
plugType	Does the plugin operate on a single source or the whole catalog (str)?
registry	List of available plugins (lsst.meas.base.PluginRegistry).

Methods Summary

calculate(cat, **kwargs)	Perform the calculation specified by this plugin.
fail(measRecord[, error])	Record a failure of the measure or measureN method.
getExecutionOrder()	Used to set the relative order of plugin execution.
getLogName()
getTransformClass()	Get the measurement transformation appropriate to this plugin.

Attributes Documentation

APCORR_ORDER = 3.0

Order for algorithms which require shape, centroid and flux (float).

Notes

These algorithms may assume that getCentroid and getShape will return good values, that flux has been measured, and that and that a Footprint and its Peaks are available.

CENTROID_ORDER = 0.0

Order for algorithms which require only Footprint and Peaks (float).

Notes

Algorithms with this execution order include centroids.

DEFAULT_CATALOGCALCULATION = 4.0

Order for catalog calculation plugins.

Notes

These plugins only operate on catalogs; they may not access pixel values.

FLUX_ORDER = 2.0

Order for algorithms which require a shape and a centroid (float).

Notes

These algorithms may assume that both getCentroid and getShape will return good values, and that a Footprint and its Peaks are available.

SHAPE_ORDER = 1.0

Order for algorithms which require a centroid (float).

Notes

These algorithms may refer assume that getCentroid will return a good centroid, and that a Footprint and its Peaks are available.

plugType = 'single'

Does the plugin operate on a single source or the whole catalog (str)?

If the plugin operates on a single source at a time, this should be set to "single"; if it expects the whoe catalog, to "multi". If the plugin is of type "multi", the fail method must be implemented to accept the whole catalog. If the plugin is of type "single", fail should accept a single source record.

registry = <lsst.meas.base.pluginRegistry.PluginRegistry object>

List of available plugins (lsst.meas.base.PluginRegistry).

Methods Documentation

calculate(cat, **kwargs)

Perform the calculation specified by this plugin.

This method can either be used to operate on a single catalog record or a whole catalog, populating it with the output defined by this plugin.

Note that results may be added to catalog records as new columns, or may result in changes to existing values.

Parameters:

catlsst.afw.table.SourceCatalog or lsst.afw.table.SourceRecord

May either be a SourceCatalog or a single SourceRecord, depending on the plugin type. Will be updated in place to contain the results of plugin execution.

**kwargs

Any additional keyword arguments that may be passed to the plugin.

fail(measRecord, error=None)

Record a failure of the measure or measureN method.

Parameters:

measRecordlsst.afw.table.SourceRecord

Table record describing the source being measured.

errorMeasurementError, optional

Only provided if the measurement failed due to a MeasurementError being raised; otherwise, will be None.

Notes

When the plugin raises an exception, framework will call BasePlugin.fail to allow the plugin to set its failure flag field(s). When BasePlugin.measureN raises an exception, BasePlugin.fail will be called repeatedly with all the records that were being measured.

If the exception is an MeasurementError, it will be passed as the error argument; in all other cases the error argument will be None, and the failure will be logged by the measurement framework as a warning.

classmethod getExecutionOrder()

Used to set the relative order of plugin execution.

The values returned by getExecutionOrder are compared across all plugins, and smaller numbers run first.

Notes

CatalogCalculationPlugins must run with BasePlugin.DEFAULT_CATALOGCALCULATION or higher.

All plugins must implement this method with an appropriate run level

getLogName()

static getTransformClass()

Get the measurement transformation appropriate to this plugin.

This returns a subclass of transforms.MeasurementTransform, which may be instantiated with details of the algorithm configuration and then called with information about calibration and WCS to convert from raw measurement quantities to calibrated units. Calibrated data is then provided in a separate output table.

Notes

By default, we copy everything from the input to the output without transformation.