def test_leftpad():
before = 10
data = np.linspace(before - 1, 0, before)
after = 3
assert_equal(leftpad(data, after), data[-after:])
after = 10
assert_equal(leftpad(data, after), data)
after = 25
lp = leftpad(data, after)
assert_equal(lp[-before:], data)
assert_equal(lp[:-before], 0)
def _calc_data_taper(self) -> np.ndarray:
""" Input data window. Zeroes out all data older than 1 frame old.
See https://github.com/jimbo1qaz/corrscope/wiki/Correlation-Trigger
"""
N = self._buffer_nsamp
halfN = N // 2
# - Create a cosine taper of `width` <= 1 frame
# - Right-pad(value=1, len=1 frame)
# - Place in left half of N-sample buffer.
# To avoid cutting off data, use a narrow transition zone (invariant to stride).
# _real_samp_frame (unit=subsample) == stride * frame.
transition_nsamp = round(self._real_samp_frame *
self.cfg.lag_prevention)
tsamp_frame = self._tsamp_frame
# Left half of a Hann cosine taper
# Width (type=subsample) = min(stride*frame * lag_prevention, 1 frame)
width = min(transition_nsamp, tsamp_frame)
taper = windows.hann(width * 2)[:width]
# Right-pad=1 taper to 1 frame long [t-1f, t]
if width < tsamp_frame:
taper = np.pad(taper, (0, tsamp_frame - width),
"constant",
constant_values=1)
assert len(taper) == tsamp_frame
# Left-pad=0 taper to left `halfN` of data_taper [t-halfN, t]
taper = leftpad(taper, halfN)
# Generate left half-taper to prevent correlating with 1-frame-old data.
# Right-pad=1 taper to [t-halfN, t-halfN+N]
# TODO why not extract a right-pad function?
data_taper = np.ones(N, dtype=FLOAT)
data_taper[:halfN] = np.minimum(data_taper[:halfN], taper)
return data_taper
def _calc_lag_prevention(self) -> np.ndarray:
""" Returns input-data window,
which zeroes out all data older than 1-ish frame old.
See https://github.com/jimbo1qaz/corrscope/wiki/Correlation-Trigger
"""
N = self._buffer_nsamp
halfN = N // 2
# - Create a cosine taper of `width` <= 1 frame
# - Right-pad(value=1, len=1 frame)
# - Place in left half of N-sample buffer.
# To avoid cutting off data, use a narrow transition zone (invariant to stride).
lag_prevention = self.cfg.lag_prevention
tsamp_frame = self._tsamp_frame
transition_nsamp = round(tsamp_frame *
lag_prevention.transition_frames)
# Left half of a Hann cosine taper
# Width (type=subsample) = min(frame * lag_prevention, 1 frame)
assert transition_nsamp <= tsamp_frame
width = transition_nsamp
taper = windows.hann(width * 2)[:width]
# Right-pad=1 taper to lag_prevention.max_frames long [t-#*f, t]
taper = rightpad(taper,
iround(tsamp_frame * lag_prevention.max_frames))
# Left-pad=0 taper to left `halfN` of data_taper [t-halfN, t]
taper = leftpad(taper, halfN)
# Generate left half-taper to prevent correlating with 1-frame-old data.
# Right-pad=1 taper to [t-halfN, t-halfN+N]
# TODO switch to rightpad()? Does it return FLOAT or not?
data_taper = np.ones(N, dtype=FLOAT)
data_taper[:halfN] = np.minimum(data_taper[:halfN], taper)
return data_taper