def decode_targetid(targetid):
"""break a DESI TARGETID into its constituent parts.
Parameters
----------
:class:`int` or :class:`~numpy.ndarray`
The TARGETID for DESI, encoded according to the bits listed in
:meth:`desitarget.targetid_mask`.
Returns
-------
:class:`int` or :class:`~numpy.ndarray`
The OBJID from Legacy Surveys imaging or the row within
a Gaia HEALPixel file in $GAIA_DIR/healpix if
`gaia` is not ``None``.
:class:`int` or :class:`~numpy.ndarray`
The BRICKID from Legacy Surveys imaging.
or the Gaia HEALPixel chunk number for files in
$GAIA_DIR/healpix if `gaia` is not ``None``.
:class:`int` or :class:`~numpy.ndarray`
The RELEASE from Legacy Surveys imaging. Or, if < 1000,
the secondary target class bit flag number from
'data/targetmask.yaml'. Or, if < 1000 and `sky` is not
``None``, the HEALPixel processing number for SUPP_SKIES.
:class:`int` or :class:`~numpy.ndarray`
1 if this object is a mock object (generated from
mocks, not from real survey data), 0 otherwise
:class:`int` or :class:`~numpy.ndarray`
1 if this object is a blank sky object, 0 otherwise
:class:`int` or :class:`~numpy.ndarray`
The Gaia Data Release number (e.g. will be 2 for Gaia DR2).
A value of 1 does NOT mean DR1. Rather it has the specific
meaning of a DESI first-light commissioning target.
Notes
-----
- if a 1-D array is passed, then an integer is returned.
Otherwise an array is returned.
- see also `DocDB 2348`_.
"""
# ADM the names of the bits with RESERVED removed.
bitnames = targetid_mask.names()
if "RESERVED" in bitnames:
bitnames.remove("RESERVED")
# ADM retrieve each value by left-shifting by the number of bits
# ADM that comprise the value, to the left-end of the value, and
# ADM then right-shifting to the right-end.
outputs = []
for bitname in bitnames:
bitnum = targetid_mask[bitname].bitnum
val = (targetid & (2**targetid_mask[bitname].nbits - 1 <<
targetid_mask[bitname].bitnum)) >> bitnum
outputs.append(val)
return outputs
def encode_targetid(objid=None,
brickid=None,
release=None,
mock=None,
sky=None,
gaiadr=None):
"""Create the DESI TARGETID from input source and imaging info.
Parameters
----------
objid : :class:`int` or :class:`~numpy.ndarray`, optional
The OBJID from Legacy Surveys imaging or the row within
a Gaia HEALPixel file in $GAIA_DIR/healpix if
`gaia` is not ``None``.
brickid : :class:`int` or :class:`~numpy.ndarray`, optional
The BRICKID from Legacy Surveys imaging.
or the Gaia HEALPixel chunk number for files in
$GAIA_DIR/healpix if `gaia` is not ``None``.
release : :class:`int` or :class:`~numpy.ndarray`, optional
The RELEASE from Legacy Surveys imaging. Or, if < 1000,
the secondary target class bit flag number from
'data/targetmask.yaml'. Or, if < 1000 and `sky` is not
``None``, the HEALPixel processing number for SUPP_SKIES.
mock : :class:`int` or :class:`~numpy.ndarray`, optional
1 if this object is a mock object (generated from
mocks, not from real survey data), 0 otherwise
sky : :class:`int` or :class:`~numpy.ndarray`, optional
1 if this object is a blank sky object, 0 otherwise
gaiadr : :class:`int` or :class:`~numpy.ndarray`, optional
The Gaia Data Release number (e.g. send 2 for Gaia DR2).
A value of 1 does NOT mean DR1. Rather it has the specific
meaning of a DESI first-light commissioning target.
Returns
-------
:class:`int` or `~numpy.ndarray`
The TARGETID for DESI, encoded according to the bits listed in
:meth:`desitarget.targetid_mask`. If an integer is passed, then
an integer is returned, otherwise an array is returned.
Notes
-----
- Has maximum flexibility so that mixes of integers and arrays
can be passed, in case some value like BRICKID or SKY
is the same for a set of objects. Consider, e.g.:
print(
targets.decode_targetid(
targets.encode_targetid(objid=np.array([234,12]),
brickid=np.array([234,12]),
release=4000,
sky=[1,0]))
)
(array([234,12]), array([234,12]), array([4000,4000]),
array([0,0]), array([1,0]))
- See also `DocDB 2348`_.
"""
# ADM a flag that tracks whether the main inputs were integers.
intpassed = True
# ADM the names of the bits with RESERVED removed.
bitnames = targetid_mask.names()
if "RESERVED" in bitnames:
bitnames.remove("RESERVED")
# ADM determine the length of passed values that aren't None.
# ADM default to an integer (length 1).
nobjs = 1
inputs = [objid, brickid, release, mock, sky, gaiadr]
goodpar = [param is not None for param in inputs]
firstgoodpar = np.where(goodpar)[0][0]
if isinstance(inputs[firstgoodpar], np.ndarray):
nobjs = len(inputs[firstgoodpar])
intpassed = False
# ADM set parameters that weren't passed to zerod arrays
# ADM set integers that were passed to at least 1D arrays
for i, param in enumerate(inputs):
if param is None:
inputs[i] = np.zeros(nobjs, dtype='int64')
else:
inputs[i] = np.atleast_1d(param)
# ADM check passed parameters don't exceed their bit-allowance.
for param, bitname in zip(inputs, bitnames):
if not np.all(param < 2**targetid_mask[bitname].nbits):
msg = 'Invalid range when making targetid: {} '.format(bitname)
msg += 'cannot exceed {}'.format(2**targetid_mask[bitname].nbits -
1)
log.critical(msg)
raise IOError(msg)
# ADM set up targetid as an array of 64-bit integers.
targetid = np.zeros(nobjs, ('int64'))
# ADM populate TARGETID. Shift to type integer 64 to avoid casting.
for param, bitname in zip(inputs, bitnames):
targetid |= param.astype('int64') << targetid_mask[bitname].bitnum
# ADM if the main inputs were integers, return an integer.
if intpassed:
return targetid[0]
return targetid