signal opsignal → measurementimport fullseye as fs; fs.ledger.zero_crossing_rate(x) (実装を直接呼ぶなら import dsp; dsp.zero_crossing_rate(x)、台帳から引くなら ops1d.get("zero_crossing_rate"))Fraction of adjacent samples that change sign — a cheap pitch/noisiness cue.
Exact zeros are neither a crossing nor a sign: a crossing is counted only when
the sign changes between consecutive non-zero samples, and the rate divides
by the number of adjacent sample pairs len(x) - 1. So [1, 0, 1, 0, 1] is
0.0 and [1, 0, -1] is 0.5 (before 2026-09-02 diff(sign(x)) counted
every touch of zero as a crossing: 1.0 for both).
measurement を入力に取れる)—
signal)lowpass · highpass · bandpass · envelope · rms · resample · spectrum · spectrogram
Provenance: dsp.py — ONED 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.