baseMeasurement.py

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#!/usr/bin/env python
#
# LSST Data Management System
# Copyright 2008-2016 AURA/LSST.
#
# This product includes software developed by the
# LSST Project (http://www.lsst.org/).
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# This program is free software: you can redistribute it and/or modify
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"""Base measurement task, which subclassed by the single frame and forced measurement tasks.
"""
import lsst.pipe.base
import lsst.pex.config

from .pluginRegistry import PluginMap
from .baseLib import FatalAlgorithmError, MeasurementError
from .pluginsBase import BasePluginConfig, BasePlugin
from .noiseReplacer import NoiseReplacerConfig

__all__ = ("BaseMeasurementPluginConfig", "BaseMeasurementPlugin",
           "BaseMeasurementConfig", "BaseMeasurementTask")

# Exceptions that the measurement tasks should always propagate up to their callers
FATAL_EXCEPTIONS = (MemoryError, FatalAlgorithmError)


class BaseMeasurementPluginConfig(BasePluginConfig):
    """!
    Base config class for all measurement plugins

    Most derived classes will want to override setDefaults() in order to customize
    the default exceutionOrder.

    A derived class whose corresponding Plugin class implements measureN() should
    additionally add a bool doMeasureN field to replace the bool class attribute
    defined here.
    """

    doMeasure = lsst.pex.config.Field(dtype=bool, default=True,
                                      doc="whether to run this plugin in single-object mode")

    doMeasureN = False  # replace this class attribute with a Field if measureN-capable


class BaseMeasurementPlugin(BasePlugin):
    '''
    Base class for all measurement plugins

    This is class is a placeholder for future behavior which will be shared only between
    measurement plugins and is implemented for symmetry with the measurement base plugin
    configuration class
    '''
    pass


class SourceSlotConfig(lsst.pex.config.Config):
    """!
    Slot configuration which assigns a particular named plugin to each of a set of
    slots.  Each slot allows a type of measurement to be fetched from the SourceTable
    without knowing which algorithm was used to produced the data.

    NOTE: the default algorithm for each slot must be registered, even if the default is not used.
    """

    centroid = lsst.pex.config.Field(dtype=str, default="base_SdssCentroid", optional=True,
                                     doc="the name of the centroiding algorithm used to set source x,y")
    shape = lsst.pex.config.Field(dtype=str, default="base_SdssShape", optional=True,
                                  doc="the name of the algorithm used to set source moments parameters")
    apFlux = lsst.pex.config.Field(dtype=str, default="base_CircularApertureFlux_12_0", optional=True,
                                   doc="the name of the algorithm used to set the source aperture flux slot")
    modelFlux = lsst.pex.config.Field(dtype=str, default="base_GaussianFlux", optional=True,
                                      doc="the name of the algorithm used to set the source model flux slot")
    psfFlux = lsst.pex.config.Field(dtype=str, default="base_PsfFlux", optional=True,
                                    doc="the name of the algorithm used to set the source psf flux slot")
    instFlux = lsst.pex.config.Field(dtype=str, default="base_GaussianFlux", optional=True,
                                     doc="the name of the algorithm used to set the source inst flux slot")
    calibFlux = lsst.pex.config.Field(dtype=str, default="base_CircularApertureFlux_12_0", optional=True,
                                      doc="the name of the flux measurement algorithm used for calibration")

    def setupSchema(self, schema):
        """Convenience method to setup a Schema's slots according to the config definition.

        This is defined in the Config class to support use in unit tests without needing
        to construct a Task object.
        """
        aliases = schema.getAliasMap()
        if self.centroid is not None:
            aliases.set("slot_Centroid", self.centroid)
        if self.shape is not None:
            aliases.set("slot_Shape", self.shape)
        if self.apFlux is not None:
            aliases.set("slot_ApFlux", self.apFlux)
        if self.modelFlux is not None:
            aliases.set("slot_ModelFlux", self.modelFlux)
        if self.psfFlux is not None:
            aliases.set("slot_PsfFlux", self.psfFlux)
        if self.instFlux is not None:
            aliases.set("slot_InstFlux", self.instFlux)
        if self.calibFlux is not None:
            aliases.set("slot_CalibFlux", self.calibFlux)


class BaseMeasurementConfig(lsst.pex.config.Config):
    """!
    Base config class for all measurement driver tasks.
    """

    slots = lsst.pex.config.ConfigField(
        dtype=SourceSlotConfig,
        doc="Mapping from algorithms to special aliases in Source."
    )

    doReplaceWithNoise = lsst.pex.config.Field(
        dtype=bool, default=True, optional=False,
        doc='When measuring, replace other detected footprints with noise?')

    noiseReplacer = lsst.pex.config.ConfigField(
        dtype=NoiseReplacerConfig,
        doc="configuration that sets how to replace neighboring sources with noise"
    )

    def validate(self):
        lsst.pex.config.Config.validate(self)
        if self.slots.centroid is not None and self.slots.centroid not in self.plugins.names:
            raise ValueError("source centroid slot algorithm is not being run.")
        if self.slots.shape is not None and self.slots.shape not in self.plugins.names:
            raise ValueError("source shape slot algorithm '%s' is not being run." % self.slots.shape)
        for slot in (self.slots.psfFlux, self.slots.apFlux, self.slots.modelFlux,
                     self.slots.instFlux, self.slots.calibFlux):
            if slot is not None:
                for name in self.plugins.names:
                    if len(name) <= len(slot) and name == slot[:len(name)]:
                        break
                else:
                    raise ValueError("source flux slot algorithm '%s' is not being run." % slot)

## @addtogroup LSST_task_documentation
## @{
## @page baseMeasurementTask
## BaseMeasurementTask @copybrief BaseMeasurementTask
## @}


class BaseMeasurementTask(lsst.pipe.base.Task):
    """!
    Ultimate base class for all measurement tasks.

    This base class for SingleFrameMeasurementTask and ForcedMeasurementTask mostly exists to share
    code between the two, and generally should not be used directly.
    """

    ConfigClass = BaseMeasurementConfig
    _DefaultName = "measurement"

    def __init__(self, algMetadata=None, **kwds):
        """!
        Constructor; only called by derived classes.

        @param[in]  algMetadata     An lsst.daf.base.PropertyList that will be filled with metadata
                                    about the plugins being run.  If None, an empty PropertyList will
                                    be created.
        @param[in]  **kwds          Additional arguments passed to lsst.pipe.base.Task.__init__.

        This attaches two public attributes to the class for use by derived classes and parent tasks:
         - plugins: an empty PluginMap, which will eventually contain all active plugins that will by
           invoked by the run() method (to be filled by subclasses).  This should be considered read-only.
         - algMetadata: a lsst.daf.base.PropertyList that will contain additional information about the
           active plugins to be saved with the output catalog (to be filled by subclasses).
        """
        super(BaseMeasurementTask, self).__init__(**kwds)
        self.plugins = PluginMap()
        if algMetadata is None:
            algMetadata = lsst.daf.base.PropertyList()
        self.algMetadata = algMetadata

    def initializePlugins(self, **kwds):
        """Initialize the plugins (and slots) according to the configuration.

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

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

        Keyword arguments are forwarded directly to plugin constructors, allowing derived
        classes to use plugins with different signatures.
        """
        # Make a place at the beginning for the centroid plugin to run first (because it's an OrderedDict,
        # adding an empty element in advance means it will get run first when it's reassigned to the
        # actual Plugin).
        if self.config.slots.centroid is not None:
            self.plugins[self.config.slots.centroid] = None
        # Init the plugins, sorted by execution order.  At the same time add to the schema
        for executionOrder, name, config, PluginClass in sorted(self.config.plugins.apply()):
            self.plugins[name] = PluginClass(config, name, metadata=self.algMetadata, **kwds)
        # In rare circumstances (usually tests), the centroid slot not be coming from an algorithm,
        # which means we'll have added something we don't want to the plugins map, and we should
        # remove it.
        if self.config.slots.centroid is not None and self.plugins[self.config.slots.centroid] is None:
            del self.plugins[self.config.slots.centroid]

    def callMeasure(self, measRecord, *args, **kwds):
        """!
        Call the measure() method on all plugins, handling exceptions in a consistent way.

        @param[in,out]  measRecord     lsst.afw.table.SourceRecord that corresponds to the object being
                                       measured, and where outputs should be written.
        @param[in]      *args          Positional arguments forwarded to Plugin.measure()
        @param[in]      **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.
                                       the rest are forwarded to Plugin.measure()

        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.
        """
        beginOrder = kwds.pop("beginOrder", None)
        endOrder = kwds.pop("endOrder", None)
        for plugin in self.plugins.iter():
            if beginOrder is not None and plugin.getExecutionOrder() < beginOrder:
                continue
            if endOrder is not None and plugin.getExecutionOrder() >= endOrder:
                break
            try:
                plugin.measure(measRecord, *args, **kwds)
            except FATAL_EXCEPTIONS:
                raise
            except MeasurementError as error:
                plugin.fail(measRecord, error)
            except Exception as error:
                self.log.warn("Error in %s.measure on record %s: %s"
                              % (plugin.name, measRecord.getId(), error))
                plugin.fail(measRecord)

    def callMeasureN(self, measCat, *args, **kwds):
        """!
        Call the measureN() method on all plugins, handling exceptions in a consistent way.

        @param[in,out]  measCat        lsst.afw.table.SourceCatalog containing records for just
                                       the source family to be measured, and where outputs should
                                       be written.
        @param[in]      beginOrder     beginning execution order (inclusive): measurements with
                                       executionOrder < beginOrder are not executed. None for no limit.
        @param[in]      endOrder       ending execution order (exclusive): measurements with
                                       executionOrder >= endOrder are not executed. None for no limit.
        @param[in]      *args          Positional arguments forwarded to Plugin.measure()
        @param[in]      **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.
                                       the rest are forwarded to Plugin.measure()

        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.
        """
        beginOrder = kwds.pop("beginOrder", None)
        endOrder = kwds.pop("endOrder", None)
        for plugin in self.plugins.iterN():
            if beginOrder is not None and plugin.getExecutionOrder() < beginOrder:
                continue
            if endOrder is not None and plugin.getExecutionOrder() >= endOrder:
                break
            try:
                plugin.measureN(measCat, *args, **kwds)
            except FATAL_EXCEPTIONS:
                raise
            except MeasurementError as error:
                for measRecord in measCat:
                    plugin.fail(measRecord, error)
            except Exception as error:
                for measRecord in measCat:
                    plugin.fail(measRecord)
                self.log.warn("Error in %s.measureN on records %s-%s: %s"
                              % (plugin.name, measCat[0].getId(), measCat[-1].getId(), error))