profile_leading_edge_radius — PROFILE measure op

Data kinds: pairsmeasurement

Call: import profileops; profileops.profile_leading_edge_radius(contour, frac=0.001, n_fit=24) (or opsprofile.get("profile_leading_edge_radius"))

Usage

> This operator's description has not been translated yet. The original text follows as it is.

前縁半径(翼弦比)。前縁近傍の点に円を当てはめる。

`frac` は前縁から弦方向にどこまでを「前縁付近」とみなすか。**この値で

答えが変わる**。鼻先は円だが、少し離れると円ではないので、窓を広げると

系統的に過大になる。NACA 4 桁の閉形式 `1.1019 * t^2` と突き合わせた

実測(点数 4001 で生成):

========== ========== ========== ========== ==========

frac NACA 0012 NACA 2412 NACA 0021 NACA 0008

========== ========== ========== ========== ==========

閉形式 0.01587 0.01587 0.04859 0.00705

0.001 0.01590 0.01594 0.04780 0.00730

0.005 0.01708 0.01716 0.04801 0.00870

0.01 0.01872 0.01880 0.04897 0.01042

0.03 0.02517 0.02526 0.05412 0.01688

========== ========== ========== ========== ==========

★ 既定は 0.001。最初 0.03 を既定にしていて、閉形式の 1.6 倍の値を

返していた(「1 % 以内」と docstring に書いたのは確かめる前の推測だった)。

厚い翼(0021)ほど鈍いので窓の影響が小さく、薄い翼(0008)ほど敏感。

実データのように点が疎な輪郭では、この窓に点が 5 つ入らないことがある ——

そのときは自動で等弧長に取り直してから当てはめる。

Detailed usage guide

profile_metrology family guide

References (sample data, literature)

• 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.

Runnable examples (verified samples that actually call this op)

profile_shape_inspectionpy -3.11 examples/profile_shape_inspection.py

Ops the type connects to (they accept measurement as input)

Same category (measure)

profile_sides · profile_thickness · profile_camber · profile_trailing_edge_gap


*Provenance: profileops.py — PROFILE 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.