fullseye

curve_locality — MATH construct op

使い方

Points k apart along the curve — how far apart are they on the plane?

The reason a space-filling curve is used for storage layout, texture tiling or rendering order is locality: neighbours in the ordering should stay neighbours in space. This op measures that directly — for each gap k it returns the mean Euclidean distance between points i and i + k.

★Why this earns its place: the claim “Hilbert has better locality than scanning row by row” is usually asserted and never measured. Here it is a table you can read: a Hilbert curve grows roughly as sqrt(k) (measured 1.00 / 1.53 / 2.12 / 3.17 / 4.29 / 6.38 at k = 1 .. 32), while a boustrophedon scan grows nearly linearly (1.00 / 1.96 / 3.79 / 7.07 / 12.12 / 16.07) — an honest, reproducible gap rather than a slogan.

Parameters

points : (N, 2) array The curve’s points in visiting order. gaps : ints Index gaps to report. Gaps at or beyond N are dropped (not an error; a short curve simply has nothing to say about a long gap).

Returns a table: gap (int), mean_distance, and ratio = the first result when the first gap is 1, otherwise the minimum mean distance; a zero base yields NaN. Thus curves of different scales can be compared directly.

Raises ValueError: not an (N, 2) array; fewer than 2 points; non-finite coordinates; every requested gap out of range.

HALCON: no operator.

ファミリ共通の入力契約(fail-closed)

mathops の全 op は入力を検証してから計算する(黙って通さない):

詳しい使い方ガイド

参考(サンプルデータ・文献)

実行できる例(この op を実際に呼ぶ検証済みサンプル)

型が繋がる次の op(table を入力に取れる)

dynsys_poincare_section · dwt_inverse · chebyshev_eval_nd

同カテゴリ(construct)

circle_packing_apollonian · ford_circles · phyllotaxis_pattern · neighbour_index_gaps · ifs_fractal · ifs_similarity_dimension · space_filling_curve


Provenance: mathops.py — MATH operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。

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