direction op• 数据种类:matrix × table → matrix
• 调用: import fullseye as fs; fs.ledger.fly_flow_from_directions(responses, lattice)(要直接调用实现,import flyvision; flyvision.fly_flow_from_directions(responses, lattice);从台账取用则 opsflyvision.get("fly_flow_from_directions"))
> 该算子的说明尚无译文,以下照原文给出。
Six directional responses per ommatidium in, one local flow vector out.
The lobula plate does not keep six numbers per point of the visual field; it
keeps the direction and strength of the motion there, split over four layers
of opposite preference. This op is that reduction, done as the vector sum on
the tangent plane that makes opposite hexagonal directions cancel exactly::
f_i = (2/6) * sum_k R[k, i] * (cos t_ik, sin t_ik)
where `t_ik` is the angle of the step to ommatidium *i*'s neighbour in
direction *k*, measured in the local tangent plane with azimuth scaled by
`cos(elevation)` so that it is an angle on the sphere rather than a
difference of coordinates. The `2/6` normalises the sum so that a
cosine-tuned set of responses of amplitude `A` returns a vector of length
`A — with six directions the raw sum is 3A`.
responses: `(6, n), the return of :func:fly_t4t5_field`.
lattice: the :func:fly_hex_lattice it was measured on (a merged eye is
refused — neighbours are local, the fit downstream is not).
Returns `(n, 2)` float64: for each ommatidium the flow component along the
local azimuth (left positive) and along the local elevation (up positive), in
the response's own units. This is the `(n, 2)` field
:func:fly_egomotion_from_flow and :func:fly_matched_filter speak.
Ommatidia at the rim, which do not have all six neighbours, return exactly
zero: a partial sum over the circle does not cancel, so keeping it would draw
a ring of inward flow around the eye and the fit downstream would read that
ring as a rotation.
Ground truth: for responses `R[k] = A cos(theta_k - theta_0)` the returned
vector has length `A and angle theta_0` exactly (regular geometry, where
the six steps are 60 degrees apart); opposite directions cancel, so a
symmetric flicker response of any size returns exactly zero.
Raises `ValueError: *responses* that is not (6, n)`, a column count
that is not the lattice's ommatidium count, non-finite entries, and any
malformed *lattice*.
• 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。
• poc_fly_optomotor_steering — py -3.11 examples/poc_fly_optomotor_steering.py
matrix 作为输入)fly_lamina_filter · fly_onoff_split · fly_t4t5_field · fly_egomotion_from_flow · fly_hs_readout
direction)*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.