fit_sphere_3d — 3D `geometry` op

• Data kinds: points → primitive

• Call: import fullseye as fs; fs.ledger.fit_sphere_3d(points) (to call the implementation directly, import match3d; match3d.fit_sphere_3d(points); from the registry, ops3d.get("fit_sphere_3d"))

Usage

Point set → a least-squares sphere (algebraic fit). Returns (center, radius). For pipe and ball metrology.

> The detailed description below is the original text — the summary and the headings are translated.

`|p|² = 2c·p + (r² − |c|²) を [2p, 1] の線形最小二乗(lstsq`)で解く代数フィット

(幾何距離の最小化ではないので、球の一部しか見えていない・ノイズが大きいと半径が偏る)。

`(N,3) で 4 点未満は ValueError。radius は sqrt(max(s + |c|², 0))` で負は 0 に clamp。

点が同一平面上・共線だと `lstsq` の最小ノルム解が黙って返る(検証は無い。残差も返さないので

`|p − c| − r` で確かめる)。

幾何距離で追い込むなら本 op の結果を初期値にして非線形最小二乗、外れ値には `ransac_sphere`。

voxel からの検出は `hough_sphere_3d`。

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.

Runnable examples (verified samples that actually call this op)

• geometry_metrology — py -3.11 examples_3d/geometry_metrology.py

Ops the type connects to (they accept `primitive` as input)

fuse_to_voxel · angle_between_lines · angle_between_planes · angle_line_plane · distance_point_plane · distance_point_line · distance_line_line · distance_segment_segment

Same category (`geometry`)

line_from_2points · plane_from_3points · angle_3points · angle_between_lines · angle_between_planes · angle_line_plane · distance_point_plane · distance_point_line

*Provenance: match3d.py — 3D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

fit_sphere_3d — 3D geometry op