sdss_objid¶

pydl.pydlutils.sdss.sdss_objid(run, camcol, field, objnum, rerun=301, skyversion=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?] 0 for now
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 : int or array of int, optional

Rerun and skyversion usually don’t change very much. If supplied, make sure the size matches all the other values.

Returns:

numpy.ndarray of numpy.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

firstField flag never set.
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]