motion op• データ種: signal × signal → signal
• 呼び出し: import fullseye as fs; fs.ledger.fly_emd_response(signal_a, signal_b, tau_s=0.05, dt_s=0.001) (実装を直接呼ぶなら import flyvision; flyvision.fly_emd_response(signal_a, signal_b, tau_s=0.05, dt_s=0.001)、台帳から引くなら opsflyvision.get("fly_emd_response"))
Hassenstein-Reichardt correlator between two adjacent ommatidial signals.
The opponent elementary motion detector::
R(t) = LP(a)(t) * b(t) - a(t) * LP(b)(t)
where `LP` is a first-order low-pass of time constant *tau_s*. Delaying one
channel and multiplying it against the other, then subtracting the mirror
pair, gives a signal whose sign is the direction of motion and whose
steady-state mean encodes the temporal frequency.
signal_a / signal_b: the two 1-D input time series (same length).
tau_s: the low-pass time constant, seconds.
dt_s: the sample interval, seconds.
Returns a 1-D float64 array `R(t)` of the same length.
Ground truth: for two sinusoids of temporal frequency `f (omega = 2 pi f`)
with a spatial phase `psi = 2 pi dphi/lambda` between them, the steady-state
mean is `R_bar = dI^2 * sin(psi) * omega tau/(1 + (omega tau)^2)` (to 5%),
which is zero at `lambda = 2 dphi (psi = pi`) and maximal at
`f = 1/(2 pi tau) independent of lambda` (pinned in the tests).
Raises `ValueError`: a non-1-D / empty / too-short (< 2) / non-finite
*signal_a* or *signal_b*, mismatched lengths, a signal over
:data:MAX_SIGNAL_POINTS, and a non-positive *tau_s* / *dt_s*.
• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。
• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。
• アルゴリズムの正典(著者・年)と用途は上記ファミリ使い方ガイドに記載。
• poc_fly_vision — py -3.11 examples/poc_fly_vision.py
signal を入力に取れる)fly_lgmd_eta · fly_tau_from_expansion · fly_dsi
motion)—
*Provenance: flyvision.py — FLYVISION operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.