lsst.meas.algorithms g1581cd22ba+b2e7114e3e
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lsst.meas.algorithms.loadReferenceObjects Namespace Reference

Classes

class  _FilterCatalog
 
class  LoadReferenceObjectsConfig
 
class  ReferenceObjectLoader
 

Functions

 getFormatVersionFromRefCat (refCat)
 
 filterRefCat (refCat, refFluxField, maxRefObjects=None, minRefMag=None, log=None)
 
 getRefFluxField (schema, filterName)
 
 getRefFluxKeys (schema, filterName)
 
 applyProperMotionsImpl (log, catalog, epoch)
 

Function Documentation

◆ applyProperMotionsImpl()

lsst.meas.algorithms.loadReferenceObjects.applyProperMotionsImpl ( log,
catalog,
epoch )
Apply proper motion correction to a reference catalog.

Adjust position and position error in the ``catalog``
for proper motion to the specified ``epoch``,
modifying the catalog in place.

Parameters
----------
log : `lsst.log.Log` or `logging.Logger`
    Log object to write to.
catalog : `lsst.afw.table.SimpleCatalog`
    Catalog of positions, containing:

    - Coordinates, retrieved by the table's coordinate key.
    - ``coord_raErr`` : Error in Right Ascension (rad).
    - ``coord_decErr`` : Error in Declination (rad).
    - ``pm_ra`` : Proper motion in Right Ascension (rad/yr,
        East positive)
    - ``pm_raErr`` : Error in ``pm_ra`` (rad/yr), optional.
    - ``pm_dec`` : Proper motion in Declination (rad/yr,
        North positive)
    - ``pm_decErr`` : Error in ``pm_dec`` (rad/yr), optional.
    - ``epoch`` : Mean epoch of object (an astropy.time.Time)
epoch : `astropy.time.Time`
    Epoch to which to correct proper motion.

Definition at line 1017 of file loadReferenceObjects.py.

◆ filterRefCat()

lsst.meas.algorithms.loadReferenceObjects.filterRefCat ( refCat,
refFluxField,
maxRefObjects = None,
minRefMag = None,
log = None )
Sub-select a number of reference objects starting from the brightest
and maxing out at the number specified by maxRefObjects.

No further trimming is done if len(refCat) > maxRefObjects after trimming
to minRefMag.

Parameters
----------
refCat : `lsst.afw.table.SimpleCatalog`
    Catalog of reference objects to trim.
refFluxField : `str`
    Field of refCat to use for flux.
maxRefObjects : `int` or `None`, optional
    Maximum number of reference objects (i.e. trim refCat down to
    this number of objects).
minRefMag : `int` or `None`, optional
    Minimum (i.e. brightest) magnitude to include in the reference
    catalog.
log : `lsst.log.Log` or `logging.Logger` or `None`, optional
    Logger object used to write out messages. If `None`, no messages
    will be logged.

Returns
-------
filteredCat : `lsst.afw.table.SimpleCatalog`
    Catalog trimmed to the maximum brightness and/or maximum number set
    in the task config from the brightest flux down.

Definition at line 862 of file loadReferenceObjects.py.

◆ getFormatVersionFromRefCat()

lsst.meas.algorithms.loadReferenceObjects.getFormatVersionFromRefCat ( refCat)
"Return the format version stored in a reference catalog header.

Parameters
----------
refCat : `lsst.afw.table.SimpleCatalog`
    Reference catalog to inspect.

Returns
-------
version : `int`
    Format version integer.

Raises
------
ValueError
    Raised if the catalog is version 0, has no metadata, or does not
    include a "REFCAT_FORMAT_VERSION" key.

Definition at line 41 of file loadReferenceObjects.py.

◆ getRefFluxField()

lsst.meas.algorithms.loadReferenceObjects.getRefFluxField ( schema,
filterName )
Get the name of a flux field from a schema.

Parameters
----------
schema : `lsst.afw.table.Schema`
    Reference catalog schema.
filterName : `str`
    Name of camera filter.

Returns
-------
fluxFieldName : `str`
    Name of flux field.

Notes
-----
Return the alias of ``anyFilterMapsToThis``, if present
else, return ``*filterName*_camFlux`` if present,
else, return ``*filterName*_flux`` if present (camera filter name
matches reference filter name), else raise an exception.

Raises
------
RuntimeError
    Raised if an appropriate field is not found.

Definition at line 942 of file loadReferenceObjects.py.

◆ getRefFluxKeys()

lsst.meas.algorithms.loadReferenceObjects.getRefFluxKeys ( schema,
filterName )
Return keys for flux and flux error.

Parameters
----------
schema : `lsst.afw.table.Schema`
    Reference catalog schema.
filterName : `str`
    Name of camera filter.

Returns
-------
keys : `tuple` of (`lsst.afw.table.Key`, `lsst.afw.table.Key`)
    Two keys:

    - flux key
    - flux error key, if present, else None

Raises
------
RuntimeError
    If flux field not found.

Definition at line 984 of file loadReferenceObjects.py.