LoadReferenceObjectsTask¶
- class lsst.meas.algorithms.LoadReferenceObjectsTask(butler=None, *args, **kwargs)¶
Bases:
Task
,ReferenceObjectLoaderBase
Abstract gen2 base class to load objects from reference catalogs.
Methods Summary
applyProperMotions
(catalog, epoch)Apply proper motion correction to a reference catalog.
Empty (clear) the metadata for this Task and all sub-Tasks.
Get schema catalogs for all tasks in the hierarchy, combining the results into a single dict.
Get metadata for all tasks.
Get the task name as a hierarchical name including parent task names.
getMetadataBox
(bbox, wcs, filterName[, ...])Return metadata about the load
getMetadataCircle
(coord, radius, filterName)Return metadata about the reference catalog being loaded.
getName
()Get the name of the task.
Get the schemas generated by this task.
Get a dictionary of all tasks as a shallow copy.
joinMatchListWithCatalog
(matchCat, sourceCat)Relink an unpersisted match list to sources and reference objects.
loadPixelBox
(bbox, wcs, filterName[, ...])Load reference objects that overlap a rectangular pixel region.
loadSkyCircle
(ctrCoord, radius, filterName)Load reference objects that overlap a circular sky region.
makeField
(doc)Make a
lsst.pex.config.ConfigurableField
for this task.makeMinimalSchema
(filterNameList, *[, ...])Make a standard schema for reference object catalogs.
makeSubtask
(name, **keyArgs)Create a subtask as a new instance as the
name
attribute of this task.timer
(name[, logLevel])Context manager to log performance data for an arbitrary block of code.
Methods Documentation
- applyProperMotions(catalog, epoch)¶
Apply proper motion correction to a reference catalog.
Adjust position and position error in the
catalog
for proper motion to the specifiedepoch
, modifying the catalog in place.- Parameters:
- catalog
lsst.afw.table.SimpleCatalog
Catalog of positions, containing at least these fields:
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 inpm_ra
(rad/yr), optional.pm_dec
Proper motion in Declination (rad/yr,North positive)
pm_decErr
: Error inpm_dec
(rad/yr), optional.epoch
: Mean epoch of object (an astropy.time.Time)
- epoch
astropy.time.Time
Epoch to which to correct proper motion. If None, do not apply PM corrections or raise if
config.requireProperMotion
is True.
- catalog
- Raises:
- RuntimeError
Raised if
config.requireProperMotion
is set but we cannot apply the proper motion correction for some reason.
- getAllSchemaCatalogs() Dict[str, Any] ¶
Get schema catalogs for all tasks in the hierarchy, combining the results into a single dict.
- Returns:
- schemacatalogs
dict
Keys are butler dataset type, values are a empty catalog (an instance of the appropriate
lsst.afw.table
Catalog type) for all tasks in the hierarchy, from the top-level task down through all subtasks.
- schemacatalogs
Notes
This method may be called on any task in the hierarchy; it will return the same answer, regardless.
The default implementation should always suffice. If your subtask uses schemas the override
Task.getSchemaCatalogs
, not this method.
- getFullMetadata() TaskMetadata ¶
Get metadata for all tasks.
- Returns:
- metadata
TaskMetadata
The keys are the full task name. Values are metadata for the top-level task and all subtasks, sub-subtasks, etc.
- metadata
Notes
The returned metadata includes timing information (if
@timer.timeMethod
is used) and any metadata set by the task. The name of each item consists of the full task name with.
replaced by:
, followed by.
and the name of the item, e.g.:topLevelTaskName:subtaskName:subsubtaskName.itemName
using
:
in the full task name disambiguates the rare situation that a task has a subtask and a metadata item with the same name.
- getFullName() str ¶
Get the task name as a hierarchical name including parent task names.
- Returns:
- fullName
str
The full name consists of the name of the parent task and each subtask separated by periods. For example:
The full name of top-level task “top” is simply “top”.
The full name of subtask “sub” of top-level task “top” is “top.sub”.
The full name of subtask “sub2” of subtask “sub” of top-level task “top” is “top.sub.sub2”.
- fullName
- getMetadataBox(bbox, wcs, filterName, epoch=None, bboxToSpherePadding=100)¶
Return metadata about the load
This metadata is used for reloading the catalog (e.g., for reconstituting a normalised match list).
- Parameters:
- bbox
lsst.geom.Box2I
orlsst.geom.Box2D
Bounding box for the pixels.
- wcs
lsst.afw.geom.SkyWcs
The WCS object associated with
bbox
.- filterName
str
Name of the camera filter.
- epoch
astropy.time.Time
orNone
, optional Epoch to which to correct proper motion and parallax, or
None
to not apply such corrections.- bboxToSpherePadding
int
, optional Padding in pixels to account for translating a set of corners into a spherical (convex) boundary that is certain to encompass the enitre area covered by the box.
- bbox
- Returns:
- md
lsst.daf.base.PropertyList
The metadata detailing the search parameters used for this dataset.
- md
- static getMetadataCircle(coord, radius, filterName, epoch=None)¶
Return metadata about the reference catalog being loaded.
This metadata is used for reloading the catalog (e.g. for reconstituting a normalized match list).
- Parameters:
- coord
lsst.geom.SpherePoint
ICRS center of the search region.
- radius
lsst.geom.Angle
Radius of the search region.
- filterName
str
Name of the camera filter.
- epoch
astropy.time.Time
orNone
, optional Epoch to which to correct proper motion and parallax, or
None
to not apply such corrections.
- coord
- Returns:
- md
lsst.daf.base.PropertyList
Metadata about the catalog.
- md
- getSchemaCatalogs() Dict[str, Any] ¶
Get the schemas generated by this task.
- Returns:
- schemaCatalogs
dict
Keys are butler dataset type, values are an empty catalog (an instance of the appropriate
lsst.afw.table
Catalog type) for this task.
- schemaCatalogs
See also
Task.getAllSchemaCatalogs
Notes
Warning
Subclasses that use schemas must override this method. The default implementation returns an empty dict.
This method may be called at any time after the Task is constructed, which means that all task schemas should be computed at construction time, not when data is actually processed. This reflects the philosophy that the schema should not depend on the data.
Returning catalogs rather than just schemas allows us to save e.g. slots for SourceCatalog as well.
- getTaskDict() Dict[str, ReferenceType[Task]] ¶
Get a dictionary of all tasks as a shallow copy.
- Returns:
- taskDict
dict
Dictionary containing full task name: task object for the top-level task and all subtasks, sub-subtasks, etc.
- taskDict
- joinMatchListWithCatalog(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:
- matchCat
lsst.afw.table.BaseCatalog
Unpersisted 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.
- matchCat
- Returns:
- matchList
lsst.afw.table.ReferenceMatchVector
Match list.
- matchList
- loadPixelBox(bbox, wcs, filterName, photoCalib=None, epoch=None)¶
Load reference objects that overlap a rectangular pixel region.
- Parameters:
- bbox
lsst.geom.Box2I
orlsst.geom.Box2D
Bounding box for pixels.
- wcs
lsst.afw.geom.SkyWcs
WCS; used to convert pixel positions to sky coordinates and vice-versa.
- filterName
str
Name of filter. This can be used for flux limit comparisons.
- photoCalib
None
Deprecated, only included for api compatibility.
- epoch
astropy.time.Time
orNone
, optional Epoch to which to correct proper motion and parallax, or
None
to not apply such corrections.
- bbox
- Returns:
- results
lsst.pipe.base.Struct
A Struct containing the following fields: refCat :
lsst.afw.catalog.SimpleCatalog
A catalog of reference objects with the standard schema, as documented in the main doc string for
LoadReferenceObjects
. The catalog is guaranteed to be contiguous.- fluxField
str
Name of flux field for specified
filterName
.
- fluxField
- results
Notes
The search algorithm works by searching in a region in sky coordinates whose center is the center of the bbox and radius is large enough to just include all 4 corners of the bbox. Stars that lie outside the bbox are then trimmed from the list.
- abstract loadSkyCircle(ctrCoord, radius, filterName, epoch=None, centroids=False)¶
Load reference objects that overlap a circular sky region.
- Parameters:
- ctrCoord
lsst.geom.SpherePoint
ICRS center of search region.
- radius
lsst.geom.Angle
Radius of search region.
- filterName
str
Name of filter. This can be used for flux limit comparisons.
- epoch
astropy.time.Time
orNone
, optional Epoch to which to correct proper motion and parallax, or
None
to not apply such corrections.- centroids
bool
, optional Add centroid fields to the loaded Schema.
loadPixelBox
expects these fields to exist.
- ctrCoord
- Returns:
- results
lsst.pipe.base.Struct
A Struct containing the following fields: refCat :
lsst.afw.catalog.SimpleCatalog
A catalog of reference objects with the standard schema, as documented in the main doc string for
LoadReferenceObjects
. The catalog is guaranteed to be contiguous.- fluxField
str
Name of flux field for specified
filterName
.
- fluxField
- results
Notes
Note that subclasses are responsible for performing the proper motion correction, since this is the lowest-level interface for retrieving the catalog.
- classmethod makeField(doc: str) ConfigurableField ¶
Make a
lsst.pex.config.ConfigurableField
for this task.- Parameters:
- doc
str
Help text for the field.
- doc
- Returns:
- configurableField
lsst.pex.config.ConfigurableField
A
ConfigurableField
for this task.
- configurableField
Examples
Provides a convenient way to specify this task is a subtask of another task.
Here is an example of use:
class OtherTaskConfig(lsst.pex.config.Config): aSubtask = ATaskClass.makeField("brief description of task")
- static makeMinimalSchema(filterNameList, *, addCentroid=False, addIsPhotometric=False, addIsResolved=False, addIsVariable=False, coordErrDim=2, addProperMotion=False, properMotionErrDim=2, addParallax=False)¶
Make a standard schema for reference object catalogs.
- Parameters:
- filterNameList
list
ofstr
List of filter names. Used to create <filterName>_flux fields.
- addIsPhotometric
bool
If True then add field “photometric”.
- addIsResolved
bool
If True then add field “resolved”.
- addIsVariable
bool
If True then add field “variable”.
- coordErrDim
int
Number of coord error fields; must be one of 0, 2, 3:
If 2 or 3: add fields “coord_raErr” and “coord_decErr”.
If 3: also add field “coord_radecErr”.
- addProperMotion
bool
If True add fields “epoch”, “pm_ra”, “pm_dec” and “pm_flag”.
- properMotionErrDim
int
Number of proper motion error fields; must be one of 0, 2, 3; ignored if addProperMotion false: - If 2 or 3: add fields “pm_raErr” and “pm_decErr”. - If 3: also add field “pm_radecErr”.
- addParallax
bool
If True add fields “epoch”, “parallax”, “parallaxErr” and “parallax_flag”.
- filterNameList
- Returns:
- schema
lsst.afw.table.Schema
Schema for reference catalog, an
lsst.afw.table.SimpleCatalog
.
- schema
Notes
Reference catalogs support additional covariances, such as covariance between RA and proper motion in declination, that are not supported by this method, but can be added after calling this method.
- makeSubtask(name: str, **keyArgs: Any) None ¶
Create a subtask as a new instance as the
name
attribute of this task.- Parameters:
- name
str
Brief name of the subtask.
- keyArgs
Extra keyword arguments used to construct the task. The following arguments are automatically provided and cannot be overridden:
“config”.
“parentTask”.
- name
Notes
The subtask must be defined by
Task.config.name
, an instance ofConfigurableField
orRegistryField
.