ConvertReferenceCatalogTask

class lsst.meas.algorithms.ConvertReferenceCatalogTask(*, output_dir=None, **kwargs)

Bases: lsst.pipe.base.Task

Class for producing HTM-indexed reference catalogs from external catalog data.

This implements an indexing scheme based on hierarchical triangular mesh (HTM). The term index really means breaking the catalog into localized chunks called shards. In this case each shard contains the entries from the catalog in a single HTM trixel

For producing catalogs this task makes the following assumptions about the input catalogs:

• RA, Dec are in decimal degrees.
• Epoch is available in a column, in a format supported by astropy.time.Time.
• There are no off-diagonal covariance terms, such as covariance between RA and Dec, or between PM RA and PM Dec. Support for such covariance would have to be added to to the config, including consideration of the units in the input catalog.

Parameters:

output_dir : str

The path to write the output files to, in a subdirectory defined by DatasetConfig.ref_dataset_name.

Attributes Summary

canMultiprocess

Methods Summary

emptyMetadata()	Empty (clear) the metadata for this Task and all sub-Tasks.
getFullMetadata()	Get metadata for all tasks.
getFullName()	Get the task name as a hierarchical name including parent task names.
getName()	Get the name of the task.
getTaskDict()	Get a dictionary of all tasks as a shallow copy.
makeField(doc)	Make a lsst.pex.config.ConfigurableField for this task.
makeSchema(dtype)	Make the schema to use in constructing the persisted catalogs.
makeSubtask(name, **keyArgs)	Create a subtask as a new instance as the name attribute of this task.
run(inputFiles)	Index a set of files comprising a reference catalog.
timer(name, logLevel)	Context manager to log performance data for an arbitrary block of code.

Attributes Documentation

canMultiprocess = False

Methods Documentation

emptyMetadata() → None

Empty (clear) the metadata for this Task and all sub-Tasks.

getFullMetadata() → lsst.pipe.base._task_metadata.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.

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”.

getName() → str

Get the name of the task.

Returns:

taskName : str

Name of the task.

See also

getFullName

getTaskDict() → Dict[str, weakref.ReferenceType[lsst.pipe.base.task.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.

classmethod makeField(doc: str) → lsst.pex.config.configurableField.ConfigurableField

Make a lsst.pex.config.ConfigurableField for this task.

Parameters:

doc : str

Help text for the field.

Returns:

configurableField : lsst.pex.config.ConfigurableField

A ConfigurableField for this task.

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")

makeSchema(dtype)

Make the schema to use in constructing the persisted catalogs.

Parameters:

dtype : numpy.dtype

Data type describing each entry in config.extra_col_names for the catalogs being ingested.

Returns:

schemaAndKeyMap : tuple of (lsst.afw.table.Schema, dict)

A tuple containing two items: - The schema for the output source catalog. - A map of catalog keys to use in filling the record

makeSubtask(name: str, **keyArgs) → 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”.

Notes

The subtask must be defined by Task.config.name, an instance of ConfigurableField or RegistryField.

run(inputFiles)

Index a set of files comprising a reference catalog.

Outputs are persisted in the butler repository.

Parameters:

inputFiles : list

A list of file paths to read.

timer(name: str, logLevel: int = 10) → Iterator[None]

Context manager to log performance data for an arbitrary block of code.

Parameters:

name : str

Name of code being timed; data will be logged using item name: Start and End.

logLevel

A logging level constant.

See also

timer.logInfo

Examples

Creating a timer context:

with self.timer("someCodeToTime"):
    pass  # code to time