pegtactile op• Data kinds: matrix → table
• Call: import fullseye as fs; fs.ledger.symmetry_order_contour(contour, K: 'int' = 24, rel: 'float' = 0.01) -> 'dict' (to call the implementation directly, import pegtactile; pegtactile.symmetry_order_contour(contour, K: 'int' = 24, rel: 'float' = 0.01) -> 'dict'; from the registry, opsdrive.get("symmetry_order_contour"))
Reads the order of n-fold symmetry from the complex Fourier coefficients of a closed contour (N, 2) = (row, col) (fourierdesc.contour_fourier_complex, resampled by arc length, orders ±K): under n-fold symmetry the only nonzero coefficients are k ≡ 1 (mod n). n is the greatest common divisor of (k − 1) over the significant k (|c_k| > rel·|c_1|, k ≠ 0, 1). If no k is significant, it is a circle (n = 0 = continuous). Orientation α̂ = arg(c₁₋ₙ c₁ⁿ⁻¹)/n (an invariant independent of the choice of start point, mod 2π/n). For n = 1, α̂ = −arg(·) from c₂ c₁⁻² — k = −1 (3× the amplitude) has a shape-dependent constant phase, so the branch (α / α + π) cannot be decided without a reference (the prototype got it wrong by 180°). Returns n, angle (rad, nan for n = 0), amps (k → |c_k|/|c_1|), sig and centroid (c₀ = (row, col)). The orientation from the 2nd-order moments is unusable for n ≥ 3 because the inertia becomes isotropic (a trap gate of the PoC). Raises ValueError: contour is not (N ≥ 8, 2), K < 6.
• 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_peg_insertion_tactile — py -3.11 examples/poc_peg_insertion_tactile.py
table as input)course_layout · course_occupancy · course_contains · world_build · world_camera · world_move · lidar_scan · rss_longitudinal_same
pegtactile)pad_params · pad_context · peg_wrench_to_pad_loads · pad_loads_to_peg_wrench · pad_shear_asymmetry · pad_marker_displacement · pad_tactile_frame · pad_tactile_read
*Provenance: pegtactile.py — DRIVE 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.