looming op• Data kinds: signal → signal
• Call: import fullseye as fs; fs.ledger.fly_lgmd_eta(theta_signal, dt_s, alpha=4.7, delay_s=0.0) (implementation को सीधे call करना हो तो import flyvision; flyvision.fly_lgmd_eta(theta_signal, dt_s, alpha=4.7, delay_s=0.0), registry से लेना हो तो opsflyvision.get("fly_lgmd_eta"))
फैलते subtended angle से LGMD/eta looming response।
> नीचे का विस्तृत विवरण मूल text में है — सारांश और headings का अनुवाद हो चुका है।
The multiplicative looming model::
eta(t) = theta'(t - delay) * exp(-alpha * theta(t - delay))
where *theta_signal* is the object's full subtended angle over time, in radians. The product of the angular expansion rate and an exponentially decaying gain gives a response that peaks a fixed time before collision.
theta_signal: the full subtended angle per sample, radians.
dt_s: the sample interval, seconds.
alpha: the gain-decay constant.
delay_s: a fixed neural delay, seconds.
Returns a 1-D float64 array eta(t) of the same length.
Ground truth: for an object of half-size l approaching at speed |v|, eta peaks at a time-to-contact of alpha*l/|v| - delay_s (Gabbiani et al. Eq. 5), where the subtended angle is exactly 2*atan(1/alpha) (Eq. 6; 24.0 degrees for alpha = 4.7) — both pinned in the tests.
Raises ValueError: a non-1-D / empty / too-short (< 3) / non-finite *theta_signal*, a signal over MAX_SIGNAL_POINTS, a non-positive *dt_s* / *alpha*, and a negative *delay_s*.
• Sample data catalog (DL URL / license) — 2-D के लिए skimage.data (BSD/public) + synthetic, 3-D के लिए real data sources (Stanford/PDS आदि) के DL URL।
• Operators का स्रोत और संदर्भ — इस op family के मूल research/methods के स्रोत।
• Algorithm का मानक स्रोत (लेखक, वर्ष) और उपयोग ऊपर की family usage guide में दिए गए हैं।
• poc_fly_vision — py -3.11 examples/poc_fly_vision.py
signal को input के रूप में लेते हैं)fly_hex_quantize · fly_emd_response · fly_tau_from_expansion · fly_dsi
looming)*Provenance: flyvision.py — FLYVISION operator registry. यह per-op note tools/opdocs.py md से अपने-आप generate होता है (हाथ से edit न करें)।*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.