class BCIDecoder(object):
"""
Decoder class
The label order of self.labels and self.label_names match likelihood orders computed by get_prob()
"""
def __init__(self, classifier=None, buffer_size=1.0, fake=False, amp_serial=None, amp_name=None):
"""
Params
------
classifier: classifier file
spatial: spatial filter to use
buffer_size: length of the signal buffer in seconds
"""
self.classifier = classifier
self.buffer_sec = buffer_size
self.fake = fake
self.amp_serial = amp_serial
self.amp_name = amp_name
if self.fake == False:
model = qc.load_obj(self.classifier)
if model == None:
self.print('Error loading %s' % model)
sys.exit(-1)
self.cls = model['cls']
self.psde = model['psde']
self.labels = list(self.cls.classes_)
self.label_names = [model['classes'][k] for k in self.labels]
self.spatial = model['spatial']
self.spectral = model['spectral']
self.notch = model['notch']
self.w_seconds = model['w_seconds']
self.w_frames = model['w_frames']
self.wstep = model['wstep']
self.sfreq = model['sfreq']
if not int(self.sfreq * self.w_seconds) == self.w_frames:
raise RuntimeError('sfreq * w_sec %d != w_frames %d' % (int(self.sfreq * self.w_seconds), self.w_frames))
if 'multiplier' in model:
self.multiplier = model['multiplier']
else:
self.multiplier = 1
# Stream Receiver
self.sr = StreamReceiver(window_size=self.w_seconds, amp_name=self.amp_name, amp_serial=self.amp_serial)
if self.sfreq != self.sr.sample_rate:
raise RuntimeError('Amplifier sampling rate (%.1f) != model sampling rate (%.1f). Stop.' % (
self.sr.sample_rate, self.sfreq))
# Map channel indices based on channel names of the streaming server
self.spatial_ch = model['spatial_ch']
self.spectral_ch = model['spectral_ch']
self.notch_ch = model['notch_ch']
self.ref_new = model['ref_new']
self.ref_old = model['ref_old']
self.ch_names = self.sr.get_channel_names()
mc = model['ch_names']
self.picks = [self.ch_names.index(mc[p]) for p in model['picks']]
if self.spatial_ch is not None:
self.spatial_ch = [self.ch_names.index(mc[p]) for p in model['spatial_ch']]
if self.spectral_ch is not None:
self.spectral_ch = [self.ch_names.index(mc[p]) for p in model['spectral_ch']]
if self.notch_ch is not None:
self.notch_ch = [self.ch_names.index(mc[p]) for p in model['notch_ch']]
if self.ref_new is not None:
self.ref_new = self.ch_names.index(mc[model['ref_new']])
if self.ref_old is not None:
self.ref_old = self.ch_names.index(mc[model['ref_old']])
# PSD buffer
psd_temp = self.psde.transform(np.zeros((1, len(self.picks), self.w_frames)))
self.psd_shape = psd_temp.shape
self.psd_size = psd_temp.size
self.psd_buffer = np.zeros((0, self.psd_shape[1], self.psd_shape[2]))
self.ts_buffer = []
else:
# Fake left-right decoder
model = None
self.psd_shape = None
self.psd_size = None
# TODO: parameterize directions using fake_dirs
self.labels = [11, 9]
self.label_names = ['LEFT_GO', 'RIGHT_GO']
def print(self, *args):
if len(args) > 0: print('[BCIDecoder] ', end='')
print(*args)
def get_labels(self):
"""
Returns
-------
Class labels numbers in the same order as the likelihoods returned by get_prob()
"""
return self.labels
def get_label_names(self):
"""
Returns
-------
Class label names in the same order as get_labels()
"""
return self.label_names
def start(self):
pass
def stop(self):
pass
def get_prob(self):
"""
Read the latest window
Returns
-------
The likelihood P(X|C), where X=window, C=model
"""
if self.fake:
# fake deocder: biased likelihood for the first class
probs = [random.uniform(0.0, 1.0)]
# others class likelihoods are just set to equal
p_others = (1 - probs[0]) / (len(self.labels) - 1)
for x in range(1, len(self.labels)):
probs.append(p_others)
time.sleep(0.0625) # simulated delay for PSD + RF
else:
self.sr.acquire()
w, ts = self.sr.get_window() # w = times x channels
w = w.T # -> channels x times
# apply filters. Important: maintain the original channel order at this point.
pu.preprocess(w, sfreq=self.sfreq, spatial=self.spatial, spatial_ch=self.spatial_ch,
spectral=self.spectral, spectral_ch=self.spectral_ch, notch=self.notch,
notch_ch=self.notch_ch, multiplier=self.multiplier)
# select the same channels used for training
w = w[self.picks]
# debug: show max - min
# c=1; print( '### %d: %.1f - %.1f = %.1f'% ( self.picks[c], max(w[c]), min(w[c]), max(w[c])-min(w[c]) ) )
# psd = channels x freqs
psd = self.psde.transform(w.reshape((1, w.shape[0], w.shape[1])))
# update psd buffer ( < 1 msec overhead )
self.psd_buffer = np.concatenate((self.psd_buffer, psd), axis=0)
self.ts_buffer.append(ts[0])
if ts[0] - self.ts_buffer[0] > self.buffer_sec:
# search speed comparison for ordered arrays:
# http://stackoverflow.com/questions/16243955/numpy-first-occurence-of-value-greater-than-existing-value
t_index = np.searchsorted(self.ts_buffer, ts[0] - 1.0)
self.ts_buffer = self.ts_buffer[t_index:]
self.psd_buffer = self.psd_buffer[t_index:, :, :] # numpy delete is slower
# assert ts[0] - self.ts_buffer[0] <= self.buffer_sec
# make a feautre vector and classify
feats = np.concatenate(psd[0]).reshape(1, -1)
# compute likelihoods
probs = self.cls.predict_proba(feats)[0]
return probs
def get_prob_unread(self):
return self.get_prob()
def get_psd(self):
"""
Returns
-------
The latest computed PSD
"""
return self.psd_buffer[-1].reshape((1, -1))
def is_ready(self):
"""
Ready to decode? Returns True if buffer is not empty.
"""
return self.sr.is_ready()
class BCIDecoder(object):
"""
Decoder class
The label order of self.labels and self.label_names match likelihood orders computed by get_prob()
"""
def __init__(self, classifier=None, buffer_size=1.0, fake=False, amp_serial=None, amp_name=None):
"""
Params
------
classifier: classifier file
spatial: spatial filter to use
buffer_size: length of the signal buffer in seconds
"""
self.classifier = classifier
self.buffer_sec = buffer_size
self.fake = fake
self.amp_serial = amp_serial
self.amp_name = amp_name
if self.fake == False:
model = qc.load_obj(self.classifier)
if model is None:
logger.error('Classifier model is None.')
raise ValueError
self.cls = model['cls']
self.psde = model['psde']
self.labels = list(self.cls.classes_)
self.label_names = [model['classes'][k] for k in self.labels]
self.spatial = model['spatial']
self.spectral = model['spectral']
self.notch = model['notch']
self.w_seconds = model['w_seconds']
self.w_frames = model['w_frames']
self.wstep = model['wstep']
self.sfreq = model['sfreq']
if 'decim' not in model:
model['decim'] = 1
self.decim = model['decim']
if not int(round(self.sfreq * self.w_seconds)) == self.w_frames:
logger.error('sfreq * w_sec %d != w_frames %d' % (int(round(self.sfreq * self.w_seconds)), self.w_frames))
raise RuntimeError
if 'multiplier' in model:
self.multiplier = model['multiplier']
else:
self.multiplier = 1
# Stream Receiver
self.sr = StreamReceiver(window_size=self.w_seconds, amp_name=self.amp_name, amp_serial=self.amp_serial)
if self.sfreq != self.sr.sample_rate:
logger.error('Amplifier sampling rate (%.3f) != model sampling rate (%.3f). Stop.' % (self.sr.sample_rate, self.sfreq))
raise RuntimeError
# Map channel indices based on channel names of the streaming server
self.spatial_ch = model['spatial_ch']
self.spectral_ch = model['spectral_ch']
self.notch_ch = model['notch_ch']
#self.ref_ch = model['ref_ch'] # not supported yet
self.ch_names = self.sr.get_channel_names()
mc = model['ch_names']
self.picks = [self.ch_names.index(mc[p]) for p in model['picks']]
if self.spatial_ch is not None:
self.spatial_ch = [self.ch_names.index(mc[p]) for p in model['spatial_ch']]
if self.spectral_ch is not None:
self.spectral_ch = [self.ch_names.index(mc[p]) for p in model['spectral_ch']]
if self.notch_ch is not None:
self.notch_ch = [self.ch_names.index(mc[p]) for p in model['notch_ch']]
# PSD buffer
#psd_temp = self.psde.transform(np.zeros((1, len(self.picks), self.w_frames // self.decim)))
#self.psd_shape = psd_temp.shape
#self.psd_size = psd_temp.size
#self.psd_buffer = np.zeros((0, self.psd_shape[1], self.psd_shape[2]))
#self.psd_buffer = None
self.ts_buffer = []
logger.info_green('Loaded classifier %s (sfreq=%.3f, decim=%d)' % (' vs '.join(self.label_names), self.sfreq, self.decim))
else:
# Fake left-right decoder
model = None
self.psd_shape = None
self.psd_size = None
# TODO: parameterize directions using fake_dirs
self.labels = [11, 9]
self.label_names = ['LEFT_GO', 'RIGHT_GO']
def get_labels(self):
"""
Returns
-------
Class labels numbers in the same order as the likelihoods returned by get_prob()
"""
return self.labels
def get_label_names(self):
"""
Returns
-------
Class label names in the same order as get_labels()
"""
return self.label_names
def start(self):
pass
def stop(self):
pass
def get_prob(self, timestamp=False):
"""
Read the latest window
Input
-----
timestamp: If True, returns LSL timestamp of the leading edge of the window used for decoding.
Returns
-------
The likelihood P(X|C), where X=window, C=model
"""
if self.fake:
# fake deocder: biased likelihood for the first class
probs = [random.uniform(0.0, 1.0)]
# others class likelihoods are just set to equal
p_others = (1 - probs[0]) / (len(self.labels) - 1)
for x in range(1, len(self.labels)):
probs.append(p_others)
time.sleep(0.0625) # simulated delay
t_prob = pylsl.local_clock()
else:
self.sr.acquire(blocking=True)
w, ts = self.sr.get_window() # w = times x channels
t_prob = ts[-1]
w = w.T # -> channels x times
# re-reference channels
# TODO: add re-referencing function to preprocess()
# apply filters. Important: maintain the original channel order at this point.
w = pu.preprocess(w, sfreq=self.sfreq, spatial=self.spatial, spatial_ch=self.spatial_ch,
spectral=self.spectral, spectral_ch=self.spectral_ch, notch=self.notch,
notch_ch=self.notch_ch, multiplier=self.multiplier, decim=self.decim)
# select the same channels used for training
w = w[self.picks]
# debug: show max - min
# c=1; print( '### %d: %.1f - %.1f = %.1f'% ( self.picks[c], max(w[c]), min(w[c]), max(w[c])-min(w[c]) ) )
# psd = channels x freqs
psd = self.psde.transform(w.reshape((1, w.shape[0], w.shape[1])))
# make a feautre vector and classify
feats = np.concatenate(psd[0]).reshape(1, -1)
# compute likelihoods
probs = self.cls.predict_proba(feats)[0]
# update psd buffer ( < 1 msec overhead )
'''
if self.psd_buffer is None:
self.psd_buffer = psd
else:
self.psd_buffer = np.concatenate((self.psd_buffer, psd), axis=0)
# TODO: CHECK THIS BLOCK
self.ts_buffer.append(ts[0])
if ts[0] - self.ts_buffer[0] > self.buffer_sec:
# search speed comparison for ordered arrays:
# http://stackoverflow.com/questions/16243955/numpy-first-occurence-of-value-greater-than-existing-value
#t_index = np.searchsorted(self.ts_buffer, ts[0] - 1.0)
t_index = np.searchsorted(self.ts_buffer, ts[0] - self.buffer_sec)
self.ts_buffer = self.ts_buffer[t_index:]
self.psd_buffer = self.psd_buffer[t_index:, :, :] # numpy delete is slower
# assert ts[0] - self.ts_buffer[0] <= self.buffer_sec
'''
if timestamp:
return probs, t_prob
else:
return probs
def get_prob_unread(self, timestamp=False):
return self.get_prob(timestamp)
def get_psd(self):
"""
Returns
-------
The latest computed PSD
"""
raise NotImplementedError('Sorry! PSD buffer is under testing.')
return self.psd_buffer[-1].reshape((1, -1))
def is_ready(self):
"""
Ready to decode? Returns True if buffer is not empty.
"""
return self.sr.is_ready()