TransformSourceTableTask¶

TransformSourceTableTask transforms the full-width source table (a source dataset) to a narrower Source Table (a sourceTable dataset) as specified by the Data Products Definition Document (DPDD). It extracts, transforms, and renames columns per a yaml specification, by default the Source.yaml in obs_package/policy. Inputs and outpus are both per-detector. The input is typically a wide table and output a narrow table appropriate for concatenating into a per-visit table by ConsolidateSourceTableTask.

It is the second of three postprocessing tasks to convert a src table to a per-visit Source Table that conforms to the standard data model. The first is WriteSourceTableTask, and the third is ConsolidateSourceTableTask.

TransformSourceTableTask is available as a command-line task, transformSourceTableTask.py.

Processing summary¶

TransformSourceTableTask

Read in source.

#. Generate functors (by instantiating a lsst.pipe.tasks.functors.CompositeFunctor) from the yaml specification. Apply functors to the columns.

Store output DataFrame in parquet-formatted sourceTable

transformSourceTableTask.py command-line interface¶

transformSourceTableTask.py REPOPATH [@file [@file2 ...]] [--output OUTPUTREPO | --rerun RERUN] [--id] [other options]

Key arguments:

REPOPATH: The input Butler repository’s URI or file path.

Key options:

--id:: The data IDs to process.

Python API summary¶

from lsst.pipe.tasks.postprocess import TransformSourceTableTask

classTransformSourceTableTask(*args, **kwargs): Transform/standardize a source catalog...

attributeconfig: Access configuration fields and retargetable subtasks.

methodrun(parq, funcs=None, dataId=None, band=None): Do postprocessing calculations...

methodrunDataRef(dataRef): Override to specify band label to run()...

Butler datasets¶

When run as the transformSourceTableTask.py command-line task, or directly through the runDataRef method, TransformSourceTableTask obtains datasets from the input Butler data repository and persists outputs to the output Butler data repository. Note that configurations for TransformSourceTableTask, and its subtasks, affect what datasets are persisted and what their content is.

Input datasets¶

source: Full-width parquet version of the src catalog. It is generated by WriteSourceTableTask

Output datasets¶

sourceTable: Source Table in parquet format (per-detector)

Retargetable subtasks¶

No subtasks.

Configuration fields¶

connections¶

Data type: lsst.pipe.base.config.Connections
Field type: ConfigField

Configurations describing the connections of the PipelineTask to datatypes

functorFile¶

Default: None
Field type: str Field (optional)

Path to YAML file specifying functors to be computed

saveMetadata¶

Default: True
Field type: bool Field

Flag to enable/disable metadata saving for a task, enabled by default.

Examples¶

The following command shows an example of how to run the task on an example HSC repository.

transformSourceTable.py /datasets/hsc/repo  --calib /datasets/hsc/repo/CALIB --rerun <rerun name> --id visit=30504  ccd=0..8^10..103

Using the python API

import os
from lsst.utils import getPackageDir
from lsst.daf.persistence import Butler
from lsst.pipe.tasks.postprocess import TransformSourceTableTask

# get input catalogs
butler = Butler('/path/to/repo')
dataId = {'visit': 30504, 'ccd': 51}
source = butler.get('source', dataId=dataId)

# setup task using the obs_subaru Source.yaml specification
config =  TransformSourceTableTask.ConfigClass()
config.functorFile = os.path.join(getPackageDir("obs_subaru"), 'policy', 'Source.yaml')
task = TransformSourceTableTask(config=config)
defaultFunctors = task.getFunctors()

# run the task to get a DataFrame
df = task.run(source, funcs=defaultFunctors, dataId=dataId)

You may also specify your own functors to apply:

import yaml
from  lsst.pipe.tasks.functors import CompositeFunctor

str = """
funcs:
    ApFlux:
        functor: LocalNanojansky
        args:
            - slot_CalibFlux_instFlux
            - slot_CalibFlux_instFluxErr
            - base_LocalPhotoCalib
            - base_LocalPhotoCalibErr
    ApFluxErr:
        functor: LocalNanojanskyErr
        args:
            - slot_CalibFlux_instFlux
            - slot_CalibFlux_instFluxErr
            - base_LocalPhotoCalib
            - base_LocalPhotoCalibErr
"""
exampleFunctors = CompositeFunctor.from_yaml(yaml.load(str))
df = task.run(source, funcs=exampleFunctors, dataId=dataId)

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