fly_onoff_split — FLYVISION lamina op

• 数据种类:matrix → matrix

• 调用: import fullseye as fs; fs.ledger.fly_onoff_split(movie, dt_s, tau_on_s=0.02, tau_off_s=0.02, rectify=True)(要直接调用实现,import flyvision; flyvision.fly_onoff_split(movie, dt_s, tau_on_s=0.02, tau_off_s=0.02, rectify=True);从台账取用则 opsflyvision.get("fly_onoff_split"))

用法

> 该算子的说明尚无译文,以下照原文给出。

Split a contrast movie into the ON and OFF channels the medulla carries.

Beyond the lamina the fly stops carrying one signed signal and carries two:

an ON channel (Mi1 / Tm3, brightening) and an OFF channel (Tm1 / Tm2,

darkening), each with its own relay dynamics. This op is that split, and it

keeps the rectification *optional* on purpose: the split was measured

downstream, in the motion response (Joesch et al., *Nature* 468:300, 2010),

while L1/L2 themselves respond linearly (Clark et al., *Neuron* 70:1165,

2011), so a pathway that rectifies at the lamina is making a claim the

recordings do not.

movie: `(T, n)` contrast, rows = time (the return of

:func:fly_lamina_filter). dt_s: sample interval, seconds.

tau_on_s / tau_off_s: the low-pass time constant of each channel, seconds.

rectify: `True half-wave rectifies (ON = max(c, 0)`,

`OFF = max(-c, 0), both >= 0); False` passes the signed contrast into

the ON channel and its negation into the OFF channel, which is the linear

L1/L2 case and lets the rectification happen downstream instead.

Returns `(T, 2n) float64: columns 0..n-1 are ON, n..2n-1` are OFF,

the same ommatidium order in each half.

Ground truth (exact, with `tau_on_s == tau_off_s` so the two channels share

one filter):

• `ON - OFF` is the low-passed input, whichever *rectify* you chose;

• with `rectify=True, ON + OFF` is the low-passed absolute value;

• a movie that never goes negative leaves the OFF channel identically zero

(and vice versa) — the split does not invent a dark event.

Raises `ValueError`: a non-2-D / too-short / non-finite *movie*, a movie

over :data:MAX_MOVIE_ELEMENTS, and a non-positive *dt_s* / *tau_on_s* /

*tau_off_s*.

详细使用指南

• fly_vision 族使用指南

参考(示例数据・文献)

• 示例数据目录(下载 URL / 许可证) —— 2-D 用 skimage.data(BSD/公有领域)加合成图,3-D 给出真实数据源(Stanford/PDS 等)的下载 URL。

• 算子来历与参考文献 —— 该算子族所依据的研究/方法出处。

• 算法的正典(作者・年份)与用途见上面的族使用指南。

可运行的示例(实际调用该算子并已验证的样例)

• poc_fly_optomotor_steering — py -3.11 examples/poc_fly_optomotor_steering.py

类型可衔接的下一个算子(可接受 matrix 作为输入)

fly_lamina_filter · fly_t4t5_field · fly_flow_from_directions · fly_egomotion_from_flow · fly_hs_readout

同类别(lamina)

fly_lamina_filter


*Provenance: flyvision.py — FLYVISION 算子登记表。本条目由 tools/opdocs.py md 自动生成(请勿手工编辑)。*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.