level op• データ種: signal → table
• 呼び出し: import fullseye as fs; fs.ledger.percentile_level(x, rate, percentiles=(10.0, 50.0, 90.0), weighting='A', ref=1.0, window_s=0.125, floor_db=-200.0) (実装を直接呼ぶなら import acoustics; acoustics.percentile_level(x, rate, percentiles=(10.0, 50.0, 90.0), weighting='A', ref=1.0, window_s=0.125, floor_db=-200.0)、台帳から引くなら opsacoustics.get("percentile_level"))
Statistical levels: L_N is the level exceeded N % of the time.
The record is cut into non-overlapping blocks of window_s seconds, each block's equivalent level is computed, and L_N is the (100-N)-th percentile of those levels. Non-overlapping rectangular blocks are used rather than an exponential time weighting because the block length is then exactly what the caller asked for and the statistic is exactly a percentile of the returned levels array — an exponential average would make the effective averaging time a function of the signal.
Returns a dict with one key per requested percentile ("L10", "L50", "L90", formatted with %g), plus levels (the per-block levels), times (block start times, s), n_blocks, block_samples, leq (the energy-equivalent level of the whole record), ref, weighting.
Note that L50 is the *median* level and leq is the *energy* level; they are different numbers whenever the signal is not stationary, and the gap between them is itself the usual measure of how fluctuating a record is.
Measured on a two-level test signal (1 s at 16 kHz, first half a 1 kHz sine of amplitude 1.0, second half the same at 0.1, Z-weighted, 0.125 s blocks, 8 blocks): L10 = -3.010300 and L90 = -23.010300 dB — exactly the two constituent levels, 20.000000 dB apart, as they must be for a 50/50 split. L50 = -13.010300 is the interpolated midpoint of the two clusters and leq = -5.977386, which is 17 dB above L90: the energy level sits near the loud half while the median sits between them. On a constant-amplitude signal all three percentiles and leq agree to 3.6e-15 dB.
Raises ValueError: everything _as_signal refuses, a percentile outside [0, 100], a non-positive window_s, a window_s longer than the record (which would give one block and make every percentile the same number while still looking like a statistic), ref <= 0.
• acoustic_condition_monitoring ファミリ ガイド
• 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。
• acoustic_condition_monitoring — py -3.11 examples/acoustic_condition_monitoring.py
table を入力に取れる)level)octave_bands · octave_spectrum · weighting_response · apply_weighting · equivalent_level
*Provenance: acoustics.py — ACOUSTICS 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.