fix: look in a win for ssf rise; cosmetics

This commit is contained in:
2026-04-28 10:10:52 +02:00
parent e506a3e580
commit d10187878d
3 changed files with 19 additions and 11 deletions

22
beat.py
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@@ -1,4 +1,5 @@
import numpy as np
import matplotlib.pyplot as plt # for debug only
class SsfZxing:
"""
@@ -7,18 +8,16 @@ class SsfZxing:
"""
t_holdoff = 0.1 #: hold-off period in sec (ignore zxings after initial rise)
# these two depend on each other.
t_range = 0.024 #: rise amplitude range in sec: +/- around transition, we check the rise amplitude. about 2*sw_sec but nb. 0.008 sec steps in fs/D rate
t_range = 0.032 #: rise amplitude range in sec: +/- around transition, we check the rise amplitude. about 2*sw_sec but nb. 0.008 sec steps in fs/D rate
sw_sec = 0.04 #: upslope width in sec (for SSF function)
ssf_rel_thres = 3 #: magic number from Zong 2003, to scale mean SSF amplitude
ssf_rel_thres = 3 #: magic number from Zong 2003, threshold from mean SSF amplitude
ssf_rel_rise = 0.8 #: minimum rise of SSF edge (from foot to peak) relative to 'ssf_th'
def __init__(self): pass
def _ssf_det_zxings(self, fs, ssf):
def _ssf_det_zxings(self, fs, ssf, ssf_th):
"""detect threshold crossings in 'ssf' signal."""
i_holdoff = int(self.t_holdoff * fs)
# TODO: check if we need lowpass instead of mean for 'ssf_th'
ssf_th = self.ssf_rel_thres * np.mean(ssf)
# threshold crossing
ssf_pk = np.pad((ssf > ssf_th).astype(int), (0,1))
ssf_pks = np.pad(ssf_pk[:-1], (1,0))
@@ -31,7 +30,7 @@ class SsfZxing:
i_range = int(self.t_range * fs)
for i in np.arange(i_range, ssf_z.shape[0]-i_range-1):
if ssf_z[i]:
rise = ssf[i+i_range] - ssf[i-i_range]
rise = np.max(ssf[i:i+i_range]) - np.min(ssf[i-i_range:i])
if rise < ssf_th * self.ssf_rel_rise:
ssf_z[i] = 0
ssf_z[-i_range:] = 0 # force-zero the bounds where we cannot check the amplitude rise
@@ -43,13 +42,15 @@ class SsfZxing:
def _ssf_function(self, fs, y):
"""sum-slope function."""
sw = int(self.sw_sec*fs)
duk = np.clip(np.diff(np.pad(y, (1,0))), a_min=0, a_max=np.inf) # left-looking window
#ssf = np.convolve(duk, slope_filter, mode='same') # centered window (acausal!)
duks = np.pad(np.cumsum(duk), (0, sw))
duks_r = np.roll(duks, sw)
ssf = (duks - duks_r)[:-sw]
return ssf
# compute threshold
# TODO: check if we need lowpass instead of mean for 'ssf_th'
ssf_th = self.ssf_rel_thres * np.mean(ssf)
return ssf, ssf_th
def get_mae_dist(ibis):
@@ -128,6 +129,11 @@ def get_mae_err(fs, freq, phase, act_ibis, debug=False):
# (in direction 2, an optimal solution is "fully sparse", "freq = 1/L", because those are the only 'est_beats' which are aligned)
mae += get_mae_err_1(fs, freq, phase, act_ibis, debug)
mae += get_mae_err_2(fs, freq, phase, act_ibis, debug)
# TODO: may need to weight these two differently
# TODO: see "2027-04-27 TestApi_0b" vs "2027-04-27 TestApi" plots [24]
# TODO: (check: is match always slightly to the left of the trough / smooth minimum?)
# TODO (if so, we may need to weight dir1 and dir2 differently -- or maybe norm by pts density??)
# (or even penalize differently instead of adding dir1 and dir2)
return mae
class RegularBeatFinder:

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@@ -9,6 +9,8 @@ def median_filter(a, w):
o[i] = np.median(sl)
return o
# nice-to: split longer segments (above 30 sec), merge very-short segments
class Segmenter:
seg_win_size_sec = 4.0 #: window size for stat. measures for segmentation, in sec
seg_win_step_sec = 1.0 #: step for segmentation, in sec

6
sqi.py
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@@ -28,14 +28,14 @@ class SigQuality:
def __init__(self): pass
def get_snr(self, fs, ssf, ssf_threshold, ssf_zxings):
def get_snr(self, fs, ssf, ssf_threshold, est_zxings):
"""Compute the Signal-to-Noise Ratio of beats, based on SSF function and detected beat locations."""
sigma = fs * self.gauss_beat_template_sigma_sec
W = int(fs * self.gauss_beat_template_win_sec)
gb = gauss(W, W//2, sigma)
# place gaussians on estimated beat locations
ssf_est = np.zeros(ssf.shape[0])
for i in ssf_zxings:
for i in est_zxings:
ssf_est += shift(ssf.shape[0], i, gb)
ssf_est /= gb[W//2] # normalize amplitude to 1.0
ssf_est = np.roll(ssf_est, int(sigma)) # shift to right (beat loc = gauss beginning, not center)
@@ -49,7 +49,7 @@ class SigQuality:
sqi_noise = np.sum(sqi_pen * (ssf**2))
# noise is everywhere, while signal is only around detected peaks - correct for this.
goal_density = np.mean(np.clip(2*sigma / np.diff(ssf_zxings), a_min=0, a_max=1))
goal_density = np.mean(np.clip(2*sigma / np.diff(est_zxings), a_min=0, a_max=1))
sqi_goal /= goal_density
sqi = 10 * (np.log10(sqi_goal) - np.log10(sqi_noise))