def _create_xcorr_inds(nchannels):
"""Create a ``MultiIndex`` for `nchannels` channels.
Parameters
----------
nchannels : int
Returns
-------
xc_inds : MultiIndex
"""
from span.tdt.spikeglobals import Indexer
channel_i, channel_j = 'channel i', 'channel j'
channel_names = channel_i, channel_j
lr = DataFrame(ndtuples(nchannels, nchannels), columns=channel_names)
left, right = lr[channel_i], lr[channel_j]
srt_idx = Indexer.sort('channel').reset_index(drop=True)
lshank, rshank = srt_idx.shank[left], srt_idx.shank[right]
lshank.name, rshank.name = 'shank i', 'shank j'
return MultiIndex.from_arrays((left, right, lshank, rshank))
def _read_tsq(self, event_name):
"""Read the metadata (TSQ) file of a TDT Tank.
Returns
-------
b : pandas.DataFrame
Recording metadata
"""
# create the path name
tsq_name = self.path + os.extsep + self.header_ext
# read in the raw data as a numpy rec array and convert to DataFrame
b = DataFrame(np.fromfile(tsq_name, dtype=self.tsq_dtype))
# zero based indexing
b.channel -= 1
b.channel = b.channel.astype(f8)
# -1s are invalid
b.channel[b.channel == -1] = np.nan
b.type = EventTypes[b.type].reset_index(drop=True)
b.format = DataTypes[b.format].reset_index(drop=True)
b.timestamp[np.logical_not(b.timestamp)] = np.nan
b.fs[np.logical_not(b.fs)] = np.nan
# fragile subtraction (i.e., what if TDT changes this value?)
b.size -= 10
# create some new indices based on the electrode array
srt = Indexer.sort('channel').reset_index(drop=True)
shank = srt.shank[b.channel].reset_index(drop=True)
tsq = b.join(shank)
# convert the event_name to a number
name = name2num(event_name)
# get the row of the metadata where its value equals the name-number
row = tsq.name == name
# make sure there's at least one event
assert row.any(), 'no event named %s in tank: %s' % (event_name,
self.path)
# get all the metadata for those events
tsq = tsq[row]
# convert to integer where possible
tsq.channel = tsq.channel.astype(int)
tsq.shank = tsq.shank.astype(int)
return tsq, row
def create_stsq(size=None, typ='stream',
name=span.utils.name2num('Spik'), nchannels=16, sort_code=0,
fmt=np.float32, fs=4882.8125,
samples_per_channel=None):
if size is None:
size = randint(2 ** 5, 2 ** 6)
if samples_per_channel is None:
samples_per_channel = randint(2 ** 6, 2 ** 7)
names = ('size', 'type', 'name', 'channel', 'sort_code', 'timestamp',
'fp_loc', 'format', 'fs', 'shank')
nsamples = samples_per_channel * nchannels
index = Int64Index(np.arange(nsamples))
size = Series(size, index=index, name='size')
typ = Series(typ, index=index, name='type')
name = Series(name, index=index, name='name')
channel = Series(np.tile(np.arange(nchannels),
(samples_per_channel, 1))[:, ::-1].ravel(),
index=index, name='channel')
sort_code = Series(sort_code, index=index, name='sort_code')
fp_loc = Series(index, name='fp_loc')
fmt = Series([fmt] * index.size, index=index, name='format')
start = randrange(100e7, 128e7)
ts = start + (size[0] / fs) * np.r_[:samples_per_channel]
ts = np.tile(ts, (nchannels, 1)).T.ravel()
timestamp = Series(ts, index=index, name='timestamp')
srt = Indexer.sort('channel').reset_index(drop=True)
shank = srt.shank[channel].reset_index(drop=True)
data = (size, typ, name, channel, sort_code, timestamp, fp_loc, fmt, fs,
shank)
return DataFrame(dict(zip(names, data)))