lsst.meas.algorithms  19.0.0-21-gf63060fa+4
Classes | Functions
lsst.meas.algorithms.loadReferenceObjects Namespace Reference

Classes

class  _FilterCatalog
 
class  LoadReferenceObjectsConfig
 
class  LoadReferenceObjectsTask
 Abstract base class to load objects from reference catalogs. More...
 
class  ReferenceObjectLoader
 

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 catalong 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` (optional)
    Epoch to which to correct proper motion and parallax,
    or None to not apply such corrections.

Definition at line 1460 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 89 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 66 of file loadReferenceObjects.py.

◆ getRefFluxField()

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

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`
    Name of camera filter.

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

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

Definition at line 691 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 732 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 57 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 46 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 1399 of file loadReferenceObjects.py.