fly_onoff_split — FLYVISION lamina op

• Datenarten: matrix → matrix

• Aufruf: import fullseye as fs; fs.ledger.fly_onoff_split(movie, dt_s, tau_on_s=0.02, tau_off_s=0.02, rectify=True) (die Implementierung direkt: import flyvision; flyvision.fly_onoff_split(movie, dt_s, tau_on_s=0.02, tau_off_s=0.02, rectify=True); aus dem Register: opsflyvision.get("fly_onoff_split"))

Verwendung

> Für diesen Operator gibt es noch keine Übersetzung. Es folgt der Originaltext unverändert.

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*.

Ausführlicher Anwendungsleitfaden

• Leitfaden zur Familie fly_vision

Referenzen (Beispieldaten, Literatur)

• Katalog der Beispieldaten (Download-URLs / Lizenzen) — 2-D nutzt skimage.data (BSD/Public Domain) plus synthetische Bilder, 3-D nennt Download-URLs echter Datenquellen (Stanford, PDS, …).

• Herkunft und Literatur der Operatoren — die Quellen der Forschung/Verfahren, auf denen diese Operatorfamilie beruht.

• Der kanonische Algorithmus (Autor, Jahr) und seine Anwendungen stehen im Familienleitfaden oben.

Ausführbare Beispiele (verifizierte Samples, die diesen Operator wirklich aufrufen)

• poc_fly_optomotor_steering — py -3.11 examples/poc_fly_optomotor_steering.py

Typkompatible Folge-Operatoren (nehmen matrix als Eingabe)

fly_lamina_filter · fly_t4t5_field · fly_flow_from_directions · fly_egomotion_from_flow · fly_hs_readout

Gleiche Kategorie (lamina)

fly_lamina_filter


*Provenance: flyvision.py — FLYVISION Operator-Registry. Diese Notiz wird von tools/opdocs.py md erzeugt (nicht von Hand bearbeiten).*

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