IngestIndexedReferenceTask¶
IngestIndexedReferenceTask
converts an external catalog for use as an LSST Science Pipelines reference catalog, using a Hierarchical Triangular Mesh (HTM) indexing scheme. The format and layout of the input data is configurable. The output data is a collection of lsst.afw.table.SimpleCatalog
files identified by their HTM pixel. This task is not available as a command-line task: see How to generate an LSST reference catalog for how to run the task.
Processing summary¶
IngestIndexedReferenceTask
uses Python multiprocessing
to ingest multiple files in parallel, configured by n_processes
.
Once it has generated the necessary multiprocessing file locks (one per output file: ~130,000 files for HTM depth=7
), it performs the following steps for each input file:
- Reads the file using the configured
file_reader
subtask (default:ReadTextCatalogTask
). - Indexes the coordinates in the input data to determine which mesh pixel they go with, and thus which output file they will be written to.
- Loops over the output pixels in this input file (where N is the number of sources in this pixel):
- Acquires the lock for this output file.
- Reads an existing output file and appends N new empty rows, or generates a new empty catalog with N rows.
- Fills in the empty rows of the catalog with the converted values from the input data.
- Writes the output file and releases the file lock.
Python API summary¶
from lsst.meas.algorithms.ingestIndexReferenceTask import IngestIndexedReferenceTask
-
class
(*args, butler=None, **kwargs)IngestIndexedReferenceTask
Class for producing and loading indexed reference catalogs
...
-
attribute
config
Access configuration fields and retargetable subtasks.
See also
See the IngestIndexedReferenceTask
API reference for complete details.
Butler datasets¶
IngestIndexedReferenceTask
does not behave in the same manner as most LSST Tasks.
When run directly through the createIndexedCatalog
method, IngestIndexedReferenceTask
reads input from a collection of non-LSST files, and persists outputs to an output Butler data repository.
Note that configurations for IngestIndexedReferenceTask
, and its subtasks, affect what the output dataset content is.
Output datasets¶
ref_cat
- An LSST-style reference catalog, consisting of one
lsst.afw.table.SimpleCatalog
per HTM pixel.
Retargetable subtasks¶
file_reader¶
- Default
lsst.meas.algorithms.readTextCatalogTask.ReadTextCatalogTask
- Field type
ConfigurableField
Configuration fields¶
coord_err_unit¶
dataset_config¶
- Data type
lsst.meas.algorithms.ingestIndexReferenceTask.DatasetConfig
- Field type
ConfigField
epoch_format¶
epoch_scale¶
id_name¶
is_photometric_name¶
is_resolved_name¶
is_variable_name¶
mag_column_list¶
mag_err_column_map¶
parallax_scale¶
pm_dec_err_name¶
pm_scale¶
Examples¶
See How to generate an LSST reference catalog for a description of how to run the task to ingest the Gaia DR2 catalog.