lsst.meas.algorithms  21.0.0-31-gbc33d95d+283f9bd92d
Classes | Functions
lsst.meas.algorithms.loadReferenceObjects Namespace Reference

Classes

class  _FilterCatalog
 
class  ReferenceObjectLoaderBase
 
class  ReferenceObjectLoader
 
class  LoadReferenceObjectsConfig
 
class  LoadReferenceObjectsTask
 

Functions

def isOldFluxField (name, units)
 
def hasNanojanskyFluxUnits (schema)
 
def getFormatVersionFromRefCat (refCat)
 
def convertToNanojansky (catalog, log, doConvert=True)
 
def getRefFluxField (schema, filterName=None)
 
def getRefFluxKeys (schema, filterName=None)
 
def joinMatchListWithCatalogImpl (refObjLoader, matchCat, sourceCat)
 
def applyProperMotionsImpl (log, catalog, epoch)
 

Function Documentation

◆ applyProperMotionsImpl()

def 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`
    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 1454 of file loadReferenceObjects.py.

◆ convertToNanojansky()

def lsst.meas.algorithms.loadReferenceObjects.convertToNanojansky (   catalog,
  log,
  doConvert = True 
)
Convert fluxes in a catalog from jansky to nanojansky.

Parameters
----------
catalog : `lsst.afw.table.SimpleCatalog`
    The catalog to convert.
log : `lsst.log.Log`
    Log to send messages to.
doConvert : `bool`, optional
    Return a converted catalog, or just identify the fields that need to be converted?
    This supports the "write=False" mode of `bin/convert_to_nJy.py`.

Returns
-------
catalog : `lsst.afw.table.SimpleCatalog` or None
    The converted catalog, or None if ``doConvert`` is False.

Notes
-----
Support for old units in reference catalogs will be removed after the
release of late calendar year 2019.
Use `meas_algorithms/bin/convert_to_nJy.py` to update your reference catalog.

Definition at line 86 of file loadReferenceObjects.py.

◆ getFormatVersionFromRefCat()

def 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` or `None`
    Format version integer, or `None` if the catalog has no metadata
    or the metadata does not include a "REFCAT_FORMAT_VERSION" key.

Definition at line 63 of file loadReferenceObjects.py.

◆ getRefFluxField()

def lsst.meas.algorithms.loadReferenceObjects.getRefFluxField (   schema,
  filterName = None 
)
Get the name of a flux field from a schema.

return the alias of "anyFilterMapsToThis", if present
else if filterName is specified:
    return "*filterName*_camFlux" if present
    else return "*filterName*_flux" if present (camera filter name
        matches reference filter name)
    else throw RuntimeError
else:
    return "camFlux", if present,
    else throw RuntimeError

Parameters
----------
schema : `lsst.afw.table.Schema`
    Reference catalog schema.
filterName : `str`, optional
    Name of camera filter. If not specified, ``defaultFilter`` needs to be
    set in the refcat loader config.

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

Raises
------
RuntimeError
    If an appropriate field is not found.

Definition at line 771 of file loadReferenceObjects.py.

◆ getRefFluxKeys()

def lsst.meas.algorithms.loadReferenceObjects.getRefFluxKeys (   schema,
  filterName = None 
)
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 820 of file loadReferenceObjects.py.

◆ hasNanojanskyFluxUnits()

def lsst.meas.algorithms.loadReferenceObjects.hasNanojanskyFluxUnits (   schema)
Return True if the units of all flux and fluxErr are correct (nJy).

Definition at line 54 of file loadReferenceObjects.py.

◆ isOldFluxField()

def lsst.meas.algorithms.loadReferenceObjects.isOldFluxField (   name,
  units 
)
Return True if this name/units combination corresponds to an
"old-style" reference catalog flux field.

Definition at line 43 of file loadReferenceObjects.py.

◆ joinMatchListWithCatalogImpl()

def lsst.meas.algorithms.loadReferenceObjects.joinMatchListWithCatalogImpl (   refObjLoader,
  matchCat,
  sourceCat 
)
Relink an unpersisted match list to sources and reference
objects.

A match list is persisted and unpersisted as a catalog of IDs
produced by afw.table.packMatches(), with match metadata
(as returned by the astrometry tasks) in the catalog's metadata
attribute. This method converts such a match catalog into a match
list, with links to source records and reference object records.

Parameters
----------
refObjLoader
    Reference object loader to use in getting reference objects
matchCat : `lsst.afw.table.BaseCatalog`
    Unperisted packed match list.
    ``matchCat.table.getMetadata()`` must contain match metadata,
    as returned by the astrometry tasks.
sourceCat : `lsst.afw.table.SourceCatalog`
    Source catalog. As a side effect, the catalog will be sorted
    by ID.

Returns
-------
matchList : `lsst.afw.table.ReferenceMatchVector`
    Match list.

Definition at line 1393 of file loadReferenceObjects.py.