tree op• データ種: table × signal → table
• 呼び出し: import fullseye as fs; fs.ledger.tree_run_length(tree, labels, background=0, zero_labels=None) (実装を直接呼ぶなら import treemorph; treemorph.tree_run_length(tree, labels, background=0, zero_labels=None)、台帳から引くなら opsgraph.get("tree_run_length"))
Expected run length (ERL) of a skeleton under a candidate labelling of its nodes.
`labels` gives, for every node of the tree table, the candidate object it falls in.
A run is a maximal connected piece of the tree whose nodes all carry the same
label and that holds at least one edge; its length is the cable inside it (an edge
belongs to a run only if both ends share the label; a lone node between two cuts is
no run). Edges touching `background` belong to no run. Runs whose label is
in `zero_labels` (objects that also cover another skeleton — a merge) count as length
0, as in Januszewski et al. 2018: a merged run is not trustworthy anywhere.
`erl = sum(l_i^2) / L with L` the whole cable — the run length a point drawn
uniformly along the skeleton finds itself in (points on cut or background edges find
length 0). Also returns `run_lengths` (one per run, merged runs already zeroed),
`runs, max_run, cable_length, cut_edges` (both ends labelled, differently),
`background_edges and merged_runs`.
Identities: `erl == L` when every node carries one non-background label;
`sum(run_lengths) + cut cable + background cable == L`; for any labelling with
`k runs and no lost cable, erl >= L / k (Cauchy-Schwarz) and erl <= max_run`;
a path of length `L cut at m equally spaced points gives exactly L / (m + 1)`;
cut at `m uniformly random points, E[erl] = 2L / (m + 2)` (Dirichlet(1, .., 1)).
Raises `ValueError: not a tree table; labels` not one integer per node,
non-finite or non-integer.
• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。
• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。
• アルゴリズムの正典(著者・年)と用途は上記ファミリ使い方ガイドに記載。
• poc_skeleton_run_length_vs_voi — py -3.11 examples/poc_skeleton_run_length_vs_voi.py
table を入力に取れる)graph_edge_consensus · graph_core_persistence · tree_morphometry · tree_sholl
tree)tree_from_swc · tree_morphometry · tree_sholl
*Provenance: treemorph.py — GRAPH 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.