SourceCatalog

class lsst.afw.table.SourceCatalog

Bases: _SourceCatalogBase

Attributes Summary

columns	a column view of the catalog
dtype
schema
table

Methods Summary

addNew()
append(record)
asAstropy([cls, copy, unviewable])	Return an astropy.table.Table (or subclass thereof) view into this catalog.
between(*args, **kwargs)	Overloaded function.
capacity(self)
cast(type_[, deep])	Return a copy of the catalog with the given type.
clear()
copy([deep])	Copy a catalog (default is not a deep copy).
equal_range(*args, **kwargs)	Overloaded function.
extend(iterable[, deep, mapper])	Append all records in the given iterable to the catalog.
extract(*patterns, **kwds)	Extract a dictionary of {<name>: <column-array>} in which the field names match the given shell-style glob pattern(s).
find(self, value[, key])
getChildren(parent, *args)	Return the subset of self for which the parent field equals the given value.
getColumnView()
getSchema(self)
getTable(self)
insert(key, value)
isContiguous(self)
isSorted(self[, key])
lower_bound(*args, **kwargs)	Overloaded function.
readFits(*args, **kwargs)	Overloaded function.
reserve(self, arg0)
resize(self, arg0)
set(self, arg0, arg1)
sort(self[, key])
subset(*args, **kwargs)	Overloaded function.
upper_bound(*args, **kwargs)	Overloaded function.
writeFits(*args, **kwargs)	Overloaded function.

Attributes Documentation

columns

a column view of the catalog

dtype = 'Source'

schema

table

Methods Documentation

addNew()

append(record)

asAstropy(cls=None, copy=False, unviewable='copy')

Return an astropy.table.Table (or subclass thereof) view into this catalog.

Parameters:

cls

Table subclass to use; None implies astropy.table.Table itself. Use astropy.table.QTable to get Quantity columns.

copybool, optional

If True, copy data from the LSST catalog to the astropy table. Not copying is usually faster, but can keep memory from being freed if columns are later removed from the Astropy view.

unviewablestr, optional

One of the following options (which is ignored if copy=`True` ), indicating how to handle field types (str and Flag) for which views cannot be constructed:

• ‘copy’ (default): copy only the unviewable fields.

• ‘raise’: raise ValueError if unviewable fields are present.

• ‘skip’: do not include unviewable fields in the Astropy Table.

Returns:

clsastropy.table.Table

Astropy view into the catalog.

Raises:

ValueError

Raised if the unviewable option is not a known value, or if the option is ‘raise’ and an uncopyable field is found.

between(*args, **kwargs)

Overloaded function.

1. between(self: lsst.afw.table._SourceCatalogBase, arg0: int, arg1: int, arg2: lsst.afw.table.KeyI) -> slice

2. between(self: lsst.afw.table._SourceCatalogBase, arg0: int, arg1: int, arg2: lsst.afw.table.KeyL) -> slice

3. between(self: lsst.afw.table._SourceCatalogBase, arg0: float, arg1: float, arg2: lsst.afw.table.KeyF) -> slice

4. between(self: lsst.afw.table._SourceCatalogBase, arg0: float, arg1: float, arg2: lsst.afw.table.KeyD) -> slice

5. between(self: lsst.afw.table._SourceCatalogBase, arg0: lsst.geom.Angle, arg1: lsst.geom.Angle, arg2: lsst.afw.table.KeyAngle) -> slice

capacity(self: lsst.afw.table._SourceCatalogBase) → int

cast(type_, deep=False)

Return a copy of the catalog with the given type.

Parameters:

type_

Type of catalog to return.

deepbool, optional

If True, clone the table and deep copy all records.

Returns:

copy

Copy of catalog with the requested type.

clear()

copy(deep=False)

Copy a catalog (default is not a deep copy).

equal_range(*args, **kwargs)

Overloaded function.

1. equal_range(self: lsst.afw.table._SourceCatalogBase, arg0: int, arg1: lsst.afw.table.KeyI) -> slice

2. equal_range(self: lsst.afw.table._SourceCatalogBase, arg0: int, arg1: lsst.afw.table.KeyL) -> slice

3. equal_range(self: lsst.afw.table._SourceCatalogBase, arg0: float, arg1: lsst.afw.table.KeyF) -> slice

4. equal_range(self: lsst.afw.table._SourceCatalogBase, arg0: float, arg1: lsst.afw.table.KeyD) -> slice

5. equal_range(self: lsst.afw.table._SourceCatalogBase, arg0: lsst.geom.Angle, arg1: lsst.afw.table.KeyAngle) -> slice

extend(iterable, deep=False, mapper=None)

Append all records in the given iterable to the catalog.

Parameters:

iterable

Any Python iterable containing records.

deepbool, optional

If True, the records will be deep-copied; ignored if mapper is not None (that always implies True).

mapperlsst.afw.table.schemaMapper.SchemaMapper, optional

Used to translate records.

extract(*patterns, **kwds)

Extract a dictionary of {<name>: <column-array>} in which the field names match the given shell-style glob pattern(s).

Any number of glob patterns may be passed (including none); the result will be the union of all the result of each glob considered separately.

Note that extract(“*”, copy=True) provides an easy way to transform a catalog into a set of writeable contiguous NumPy arrays.

This routines unpacks Flag columns into full boolean arrays. String fields are silently ignored.

Parameters:

patternsArray of str

List of glob patterns to use to select field names.

kwdsdict

Dictionary of additional keyword arguments. May contain:

itemslist

The result of a call to self.schema.extract(); this will be used instead of doing any new matching, and allows the pattern matching to be reused to extract values from multiple records. This keyword is incompatible with any position arguments and the regex, sub, and ordered keyword arguments.

wherearray index expression

Any expression that can be passed as indices to a NumPy array, including slices, boolean arrays, and index arrays, that will be used to index each column array. This is applied before arrays are copied when copy is True, so if the indexing results in an implicit copy no unnecessary second copy is performed.

copybool

If True, the returned arrays will be contiguous copies rather than strided views into the catalog. This ensures that the lifetime of the catalog is not tied to the lifetime of a particular catalog, and it also may improve the performance if the array is used repeatedly. Default is False. Copies are always made if the catalog is noncontiguous, but if copy=False these set as read-only to ensure code does not assume they are views that could modify the original catalog.

regexstr or re pattern

A regular expression to be used in addition to any glob patterns passed as positional arguments. Note that this will be compared with re.match, not re.search.

substr

A replacement string (see re.MatchObject.expand) used to set the dictionary keys of any fields matched by regex.

orderedbool

If True, a collections.OrderedDict will be returned instead of a standard dict, with the order corresponding to the definition order of the Schema. Default is False.

Returns:

ddict

Dictionary of extracted name-column array sets.

Raises:

ValueError

Raised if a list of items is supplied with additional keywords.

find(self: object, value: object, key: object = None) → object

getChildren(parent, *args)

Return the subset of self for which the parent field equals the given value.

In order for this method to return the correct result, it must be sorted by parent (i.e. self.isSorted(SourceTable.getParentKey()) must be True). This is naturally the case with SourceCatalogs produced by the detection and deblending tasks, but it may not be true when concatenating multiple such catalogs.

Additional Catalogs or sequences whose elements correspond in order to the records of self (i.e. zip(self, *args) is valid) will be subset using the same slice object used on self, and these subsets will be returned along with the subset of self.

Parameters:

parentint or iterable of int

ID(s) of the parent(s) to get children for.

argsCatalog

Additional catalogs to subset for the children to return.

Returns:

childrena single iterable of SourceRecord

Children sources if parent is of type int, or a generator yielding a SourceRecord`s Children sources for each parent if ``parent` is an iterable.

Raises:

AssertionError

Raised if the catalog is not sorted by the parent key.

Notes

Each call to this function checks if the catalog is sorted, which is of O(n) complexity, while fetching the children is of O(log n). To minimize the computational overhead, it is preferable to prepare an iterable of parent ids for which the children need to be fetched and pass the iterable as parent.

getColumnView()

getSchema(self: lsst.afw.table._SourceCatalogBase) → lsst.afw.table.Schema

getTable(self: lsst.afw.table._SourceCatalogBase) → lsst.afw.table.SourceTable

insert(key, value)

isContiguous(self: lsst.afw.table._SourceCatalogBase) → bool

isSorted(self: object, key: object = None) → object

lower_bound(*args, **kwargs)

Overloaded function.

1. lower_bound(self: lsst.afw.table._SourceCatalogBase, arg0: int, arg1: lsst.afw.table.KeyI) -> int

2. lower_bound(self: lsst.afw.table._SourceCatalogBase, arg0: int, arg1: lsst.afw.table.KeyL) -> int

3. lower_bound(self: lsst.afw.table._SourceCatalogBase, arg0: float, arg1: lsst.afw.table.KeyF) -> int

4. lower_bound(self: lsst.afw.table._SourceCatalogBase, arg0: float, arg1: lsst.afw.table.KeyD) -> int

5. lower_bound(self: lsst.afw.table._SourceCatalogBase, arg0: lsst.geom.Angle, arg1: lsst.afw.table.KeyAngle) -> int

static readFits(*args, **kwargs)

Overloaded function.

1. readFits(filename: str, hdu: int = -2147483648, flags: int = 0) -> lsst.afw.table.SourceCatalog

2. readFits(manager: lsst.afw.fits._fits.MemFileManager, hdu: int = -2147483648, flags: int = 0) -> lsst.afw.table.SourceCatalog

reserve(self: lsst.afw.table._SourceCatalogBase, arg0: int) → None

resize(self: lsst.afw.table._SourceCatalogBase, arg0: int) → None

set(self: lsst.afw.table._SourceCatalogBase, arg0: int, arg1: lsst.afw.table.SourceRecord) → None

sort(self: object, key: object = None) → object

subset(*args, **kwargs)

Overloaded function.

1. subset(self: lsst.afw.table.SourceCatalog, arg0: numpy.ndarray) -> lsst.afw.table.SourceCatalog

2. subset(self: lsst.afw.table.SourceCatalog, arg0: int, arg1: int, arg2: int) -> lsst.afw.table.SourceCatalog

upper_bound(*args, **kwargs)

Overloaded function.

1. upper_bound(self: lsst.afw.table._SourceCatalogBase, arg0: int, arg1: lsst.afw.table.KeyI) -> int

2. upper_bound(self: lsst.afw.table._SourceCatalogBase, arg0: int, arg1: lsst.afw.table.KeyL) -> int

3. upper_bound(self: lsst.afw.table._SourceCatalogBase, arg0: float, arg1: lsst.afw.table.KeyF) -> int

4. upper_bound(self: lsst.afw.table._SourceCatalogBase, arg0: float, arg1: lsst.afw.table.KeyD) -> int

5. upper_bound(self: lsst.afw.table._SourceCatalogBase, arg0: lsst.geom.Angle, arg1: lsst.afw.table.KeyAngle) -> int

writeFits(*args, **kwargs)

Overloaded function.

1. writeFits(self: lsst.afw.table._SourceCatalogBase, filename: str, mode: str = ‘w’, flags: int = 0) -> None

2. writeFits(self: lsst.afw.table._SourceCatalogBase, manager: lsst.afw.fits._fits.MemFileManager, mode: str = ‘w’, flags: int = 0) -> None