def gluecache_to_FrCache(cache):
"""
Convert a glue.lal.Cache object to a lalframe.FrCache object.
Writes cache to temporary file and reads to FrCache.
Arguments:
cache : glue.lal.Cache
LAL cache object from GLUE to convert
"""
with tempfile.NamedTemporaryFile(delete=False) as t:
cache = cache
for e in cache:
e.segment = type(e.segment)(int(e.segment[0]), int(e.segment[1]))
cache.tofile(t)
frcache = lal.CacheImport(t.name)
os.remove(t.name)
return frcache
def fromlalcache(cache, chname, start=-1, duration=1, datatype=-1,\
verbose=False):
"""
Read data from a cache object into a REAL?TimeSeries.
Restrict data with the gpsstart and duration parameters.
Arguments:
cache : [ filepath | file | glue.lal.Cache | lalframe.FrCache ]
object to be read to lalframe.FrCache
chname : str
name of channel to read
Keyword arguments:
start : lal.LIGOTimeGPS
GPS start time of requested data
duration : float
length of requested data series in seconds
datatype : int
LAL enum for requested datatype, -1 == read from frame metadata
verbose : [ True | False ]
verbose output
"""
# read cache from file object into gluecache for the time being
if hasattr(cache, 'readline'):
cache = gluecache.Cache.fromfile(cache)
# read cache from glue.lal.Cache, or lalframe.FrCache, or file
if cache and isinstance(cache, _gluecache.Cache):
cache.sort(key=lambda e: e.segment[0])
cache = gluecache_to_FrCache(cache)
elif isinstance(cache, str):
cache = lal.CacheImport(cache)
# open cache to stream
stream = lalframe.FrCacheOpen(cache)
# return
series = fromFrStream(stream, chname, start=start, duration=duration,\
datatype=datatype, verbose=verbose)
return series
def read_timeseries(source,
channel,
start=None,
duration=None,
datatype=None,
verbose=False):
r"""Read a TimeSeries of channel data from a source.
Acceptable sources are:
- a .gwf-format framefile (string ending in '.gwf')
- a LAL-format cache file (string ending in '.lcf' or '.cache')
- a lal.Cache object (either from SWIG-LAL or GLUE)
@param source
input source, see above for details
@param channel
string name of channel, e.g. 'L1:LDAS-STRAIN', or a list of channel
names
@param start
LIGOTimeGPS start time for output TimeSeries
@param duration
float duration (seconds) for output TimeSeries
@param datatype
datatype, either an integer from the LALTYPECODE, a string
matchine the corresponding type, or a numpy dtype
@param verbose
print verbose output, default: False
@returns a TimeSeries of the imported data
Example 1, reading from a frame file:
\code
>>> out = read_timeseries('L-R-1061499968-32.gwf', 'L1:PSL-ISS_PDB_OUT_DQ')
>>> print(type(out))
<type 'REAL4TimeSeries'>
>>> print(out.name, float(out.epoch), out.deltaT)
('L1:PSL-ISS_PDB_OUT_DQ', 1061499968.0, 3.0517578125e-05)
\endcode
Example 2, reading from a cache:
\code
>>> import lal
>>> cache = lal.CacheGlob('/scratch/ER4/L0/L1/L-R-10614', 'L-R-1061499968*')
>>> out = frread.read_timeseries(cache, 'L1:PSL-ISS_PDB_OUT_DQ')
>>> print(out.name, float(out.epoch), out.deltaT)
('L1:PSL-ISS_PDB_OUT_DQ', 1061499968.0, 3.0517578125e-05)
\endcode
Example 3, restricting data input:
\code
>>> out = read_timeseries('L-R-1061499968-32.gwf', 'L1:PSL-ISS_PDB_OUT_DQ',
start=1061499970, duration=10)
>>> print(out.name, float(out.epoch), out.data.length)
('L1:PSL-ISS_PDB_OUT_DQ', 1061499970.0, 327680)
\endcode
Example 4, specifying data type:
\code
>>> out = read_timeseries('L-R-1061499968-32.gwf',
'L1:PSL-ODC_CHANNEL_OUT_DQ')
>>> print(type(out), out.data.data[:4])
(<type 'REAL4TimeSeries'>,
array([ 4259839., 4259839., 4259839., 4259839.], dtype=float32))
>>> out = read_timeseries('L-R-1061499968-32.gwf',
'L1:PSL-ODC_CHANNEL_OUT_DQ', datatype='int8')
>>> print(type(out), out.data.data[:4])
(<type 'INT8TimeSeries'>, array([4259839, 4259839, 4259839, 4259839]))
\endcode
"""
# parse channels
if isinstance(channel, string_types):
channels = [channel]
else:
channels = list(channel)
# read cache file
if (isinstance(source, string_types)
and re.search(r'(.lcf|.cache)\Z', source)):
source = lal.CacheImport(os.path.expanduser(source))
# convert GLUE cache file
if _HAS_GLUE and isinstance(source, gcache.Cache):
source = lalutils.lalcache_from_gluecache(source)
# read from single frame
if isinstance(source, string_types) and source.endswith('.gwf'):
out = ts_from_frame_file(source,
channels,
start=start,
duration=duration,
datatype=datatype,
verbose=verbose)
# read from XLALCache
elif isinstance(source, lal.Cache):
out = ts_from_cache(source,
channels,
start=start,
duration=duration,
datatype=datatype,
verbose=verbose)
# otherwise barf
else:
raise ValueError("Cannot interpret source '%s'." % source)
# return
if isinstance(channel, string_types):
return out[0]
else:
return out