tuning op• Data kinds: signal → table
• Call: import fullseye as fs; fs.ledger.fly_dsi(responses, angles_deg) (to call the implementation directly, import flyvision; flyvision.fly_dsi(responses, angles_deg); from the registry, opsflyvision.get("fly_dsi"))
Direction-selectivity index and preferred direction from tuning responses.
A vector sum on the circle::
DSI = |sum_k r_k exp(i theta_k)| / (sum_k r_k + 1e-9)
preferred = angle(sum_k r_k exp(i theta_k))
where r_k >= 0 is the response to a stimulus moving at angle theta_k = angles_deg[k] (negatives clipped to 0).
responses: a 1-D array of responses, one per direction.
angles_deg: the stimulus directions in degrees, same length.
Returns a dict {"dsi": float, "pref_deg": float} with pref_deg in [-180, 180].
Ground truth: a response at a single direction gives dsi == 1; an isotropic response over directions evenly spanning the circle gives dsi == 0 (pinned in the tests).
Raises ValueError: a non-1-D / empty / non-finite *responses* or *angles_deg*, mismatched lengths, an array over MAX_SIGNAL_POINTS, and an all-zero *responses* (no direction tuning to report).
• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).
• Operator provenance and references — the sources of the research/methods this op family came from.
• The canonical algorithm (author, year) and its uses are named in the family usage guide above.
• poc_fly_vision — py -3.11 examples/poc_fly_vision.py
table as input)fly_t4t5_field · fly_flow_from_directions · fly_matched_filter · fly_egomotion_from_flow · fly_eye_merge · fly_hex_resample · fly_hs_readout
tuning)—
*Provenance: flyvision.py — FLYVISION operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.