@audio/mir-tonnetz

Tonal centroid (Tonnetz) — projects a 12-bin chroma vector onto three interval circles (fifths, minor thirds, major thirds), giving a 6-D harmonic-change feature (Harte, Sandler & Gasser, 2006).

npm install @audio/mir-tonnetz

import tonnetz from '@audio/mir-tonnetz'

let tz = tonnetz(chromaVec)
// Float32Array[6] — [fifths.sin, fifths.cos, minor3rds.sin, minor3rds.cos, major3rds.sin, major3rds.cos]

No options — tonnetz() takes a length-12 chroma vector (any normalization) and returns a fixed 6-D point. Consecutive Tonnetz points that jump far apart flag harmonic change (chord/key boundaries); a static point means harmonic stasis. Zero-energy chroma maps to the zero vector.

Also exported as an audio.js stat manifest (./audio) — Tonnetz frames over time (via @audio/mir-chroma internally) plus their mean.

Part of @audio/mir.