lsst.pipe.tasks.coaddHelpers Namespace Reference

Functions
def	groupDataRefs (keys, dataRefIterable)
def	groupPatchExposures (patchDataRef, calexpDataRefList, coaddDatasetType="deepCoadd", tempExpDatasetType="deepCoadd_directWarp")
def	getGroupDataId (groupTuple, keys)
def	getGroupDataRef (butler, datasetType, groupTuple, keys)

Function Documentation

getGroupDataId()

def lsst.pipe.tasks.coaddHelpers.getGroupDataId	(		groupTuple,
			keys
	)

Reconstitute a data identifier from a tuple and corresponding keys

@param groupTuple: Tuple with values specifying a group
@param keys: List of keys for group tuple
@return Data identifier dict

Definition at line 87 of file coaddHelpers.py.

def getGroupDataId(groupTuple, keys):
    """Reconstitute a data identifier from a tuple and corresponding keys
 
    @param groupTuple: Tuple with values specifying a group
    @param keys: List of keys for group tuple
    @return Data identifier dict
    """
    if len(groupTuple) != len(keys):
        raise RuntimeError("Number of values (%d) and keys (%d) do not match" % (len(groupTuple), len(keys)))
    return dict(zip(keys, groupTuple))
 
 

getGroupDataRef()

def lsst.pipe.tasks.coaddHelpers.getGroupDataRef	(		butler,
			datasetType,
			groupTuple,
			keys
	)

Construct a data reference from a tuple and corresponding keys

@param butler: Data butler
@param datasetType: Name of dataset
@param groupTuple: Tuple with values specifying a group
@param keys: List of keys for group tuple
@return Data reference

Definition at line 99 of file coaddHelpers.py.

def getGroupDataRef(butler, datasetType, groupTuple, keys):
    """Construct a data reference from a tuple and corresponding keys
 
    @param butler: Data butler
    @param datasetType: Name of dataset
    @param groupTuple: Tuple with values specifying a group
    @param keys: List of keys for group tuple
    @return Data reference
    """
    dataId = getGroupDataId(groupTuple, keys)
    return butler.dataRef(datasetType=datasetType, dataId=dataId)

groupDataRefs()

def lsst.pipe.tasks.coaddHelpers.groupDataRefs	(		keys,
			dataRefIterable
	)

Group data references by data identifier value-tuple.

Value-tuples are built from the values of the given keys.
The effect is that the data references in each group have the same
values for the provided keys.

@param keys: List of keys to consider when grouping (order is important)
@param dataRefIterable: Iterable of data references to group
@return Dict of <value-tuple>: <list of data references for group>

Definition at line 35 of file coaddHelpers.py.

def groupDataRefs(keys, dataRefIterable):
    """Group data references by data identifier value-tuple.
 
    Value-tuples are built from the values of the given keys.
    The effect is that the data references in each group have the same
    values for the provided keys.
 
    @param keys: List of keys to consider when grouping (order is important)
    @param dataRefIterable: Iterable of data references to group
    @return Dict of <value-tuple>: <list of data references for group>
    """
    groupDict = dict()
    for dataRef in dataRefIterable:
        dataId = dataRef.dataId
        values = tuple(dataId[key] for key in keys)  # NOT dataId.values() as we must preserve order
        group = groupDict.get(values)
        if group:
            group.append(dataRef)
        else:
            groupDict[values] = [dataRef]
 
    return groupDict
 
 

groupPatchExposures()

def lsst.pipe.tasks.coaddHelpers.groupPatchExposures	(		patchDataRef,
			calexpDataRefList,
			coaddDatasetType = "deepCoadd",
			tempExpDatasetType = "deepCoadd_directWarp"
	)

Group calibrated exposures overlapping a patch by the warped
(temporary) exposure they contribute to.

For example, if the instrument has a mosaic camera, each group would
consist of the subset of CCD exposures from a single camera exposure
that potentially overlap the patch.

@return Struct with:
- groups: Dict of <group tuple>: <list of data references for group>
- keys: List of keys for group tuple

Definition at line 59 of file coaddHelpers.py.

                        tempExpDatasetType="deepCoadd_directWarp"):
    """Group calibrated exposures overlapping a patch by the warped
    (temporary) exposure they contribute to.
 
    For example, if the instrument has a mosaic camera, each group would
    consist of the subset of CCD exposures from a single camera exposure
    that potentially overlap the patch.
 
    @return Struct with:
    - groups: Dict of <group tuple>: <list of data references for group>
    - keys: List of keys for group tuple
    """
    butler = patchDataRef.getButler()
    tempExpKeys = butler.getKeys(datasetType=tempExpDatasetType)
    coaddKeys = sorted(butler.getKeys(datasetType=coaddDatasetType))
    keys = sorted(set(tempExpKeys) - set(coaddKeys))  # Keys that will specify an exposure
    patchId = patchDataRef.dataId
    groups = groupDataRefs(keys, calexpDataRefList)
 
    # Supplement the groups with the coadd-specific information (e.g., tract, patch; these are constant)
    coaddValues = tuple(patchId[k] for k in coaddKeys)
    groups = dict((k + coaddValues, v) for k, v in groups.items())
    keys += tuple(coaddKeys)
 
    return Struct(groups=groups, keys=keys)