fly_egomotion_from_flow — FLYVISION selfmotion op

• 데이터 종류: matrix × table → table

• 호출: import fullseye as fs; fs.ledger.fly_egomotion_from_flow(flow, lattice, axes=None, weights=None)(구현을 직접 호출하려면 import flyvision; flyvision.fly_egomotion_from_flow(flow, lattice, axes=None, weights=None), 원장에서 가져오려면 opsflyvision.get("fly_egomotion_from_flow"))

사용법

> 이 연산자의 설명은 아직 번역이 없습니다. 원문을 그대로 싣습니다.

Least-squares rotation of the eye from its flow field — and how badly the

eye's own shape conditions the answer.

Given the flow `f_i at known viewing directions d_i`, a pure rotation

`w predicts f_i = -(w x d_i)`, which is linear in w: projecting on

the tangent basis gives `f_az = -w . (d x e_az)` and

`f_el = -w . (d x e_el), so the estimate is one 2n x 3` least-squares

solve with no iteration and no starting guess (Franz et al.'s linear

egomotion estimate, *Biol. Cybern.* 2004).

The catch is not the algebra, it is the eye. A single patch of ommatidia sees

a small piece of the sphere, and over a small piece the flow of a yaw and the

flow of a sideways translation — or of a pitch — look nearly the same. This

op therefore returns the condition number of that solve next to the

answer, so that "the fit converged" and "the fit was identifiable" stay

separate claims.

flow: `(n, 2)` azimuth/elevation components per ommatidium

(:func:fly_flow_from_directions or :func:fly_matched_filter).

lattice: the eye they were measured on.

axes: `None to solve for the full 3-D rotation, or a (k, 3)` array of

axes to restrict the fit to (`[[0, 0, 1]]` = yaw only, the well-conditioned

question a forward-looking eye can actually answer).

weights: `None or (n,)` non-negative per-ommatidium weights — a

confidence, e.g. the local contrast, or zeros to drop the rim.

Returns a dict::

{"omega_rad_s": (3,), "yaw_rad_s": float, "pitch_rad_s": float,

"roll_rad_s": float, "residual_rms": float, "flow_rms": float,

"explained": float, "condition": float, "n_ommatidia": int}

with yaw about +z (left positive), pitch about +y, roll about +x, and

`explained = 1 - residual_rms/flow_rms` (1.0 = the flow is exactly a

rotation, 0.0 = the fit explains none of it).

Ground truth: handed a :func:fly_matched_filter template scaled by a known

rate, it returns that rate to machine precision and `explained = 1`; handed

a pure translation field it returns a small rate with a low `explained`; and

the condition number of a narrow forward eye is large (the tests measure it)

while the yaw-only fit is near 1.

Raises `ValueError: a *flow* that is not (n, 2)` for this lattice,

non-finite entries, a malformed *axes* / *weights*, all-zero weights, and a

lattice with fewer ommatidia than the fit has unknowns.

자세한 사용 가이드

• fly_vision 패밀리 가이드

참고(샘플 데이터·문헌)

• 샘플 데이터 카탈로그(DL URL / 라이선스) —— 2-D 는 skimage.data(BSD/public)+ 합성, 3-D 는 실데이터 소스(Stanford/PDS 등)의 DL URL.

• 연산자의 내력·참고문헌 —— 이 연산자 족의 바탕이 된 연구/기법의 출처.

• 알고리즘의 정전(저자·연도)과 용도는 위의 패밀리 사용 가이드에 적혀 있습니다.

실행 가능한 예제(이 연산자를 실제로 호출하는 검증된 샘플)

• poc_fly_optomotor_steering — py -3.11 examples/poc_fly_optomotor_steering.py

타입이 이어지는 다음 연산자(table 를 입력으로 받는 것)

fly_t4t5_field · fly_flow_from_directions · fly_matched_filter · fly_eye_merge · fly_hex_resample · fly_hs_readout

같은 카테고리(selfmotion)

fly_matched_filter · fly_eye_merge


*Provenance: flyvision.py — FLYVISION 연산자 레지스트리. 이 op 노트는 tools/opdocs.py md 가 자동 생성합니다(직접 편집하지 마세요).*

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