sdss_objid¶
- pydl.pydlutils.sdss.sdss_objid(run, camcol, field, objnum, rerun=301, skyversion=None, firstfield=None)[source]¶
Convert SDSS photometric identifiers into CAS-style ObjID.
Bits are assigned in ObjID thus:
Bits
Name
Comment
63
empty
unassigned
59-62
skyVersion
resolved sky version (0-15)
48-58
rerun
number of pipeline rerun
32-47
run
run number
29-31
camcol
camera column (1-6)
28
firstField
is this the first field in segment? Usually 0.
16-27
field
field number within run
0-15
object
object number within field
- Parameters:
- run, camcol, field, objnum
int
or array of int Run, camcol, field and object number within field. If arrays are passed, all must have the same length.
- rerun, skyversion, firstfield
int
or array of int, optional rerun
,skyversion
andfirstfield
usually don’t change at all, especially for ObjIDs in DR8 and later. If supplied, make sure the size matches all the other values.
- run, camcol, field, objnum
- Returns:
numpy.ndarray
ofnumpy.int64
The ObjIDs of the objects.
- Raises:
ValueError
If the sizes of the arrays don’t match or if the array values are out of bounds.
Notes
The
firstField
flag is never set in ObjIDs from DR8 and later.On 32-bit systems, makes sure to explicitly declare all inputs as 64-bit integers.
Examples
>>> from pydl.pydlutils.sdss import sdss_objid >>> print(sdss_objid(3704,3,91,146)) [1237661382772195474]