librosax.feature.tonnetz

tonnetz(*, y: Array | None = None, sr: float = 22050, chroma: Array | None = None, **kwargs) → Array[source]

Compute the tonal centroid features (tonnetz).

This representation projects chroma features onto a 6-dimensional basis representing the perfect fifth, minor third, and major third each as two-dimensional coordinates.

Parameters:

  • y –

    Audio time series. The last axis must be time.

    • (T,) - single waveform

    • (B, T) - batch of waveforms

  • sr – Sampling rate of y

  • chroma – Normalized energy for each chroma bin at each frame with shape (..., n_chroma, N). If None, a chroma_stft is computed.

  • **kwargs – Additional keyword arguments to chroma_stft, if chroma is not pre-computed.

Returns:

Tonnetz features with shape (..., 6, N).

  • (T,) → (6, N)

  • (B, T) → (B, 6, N)

Tonnetz dimensions:

  • 0: Fifth x-axis

  • 1: Fifth y-axis

  • 2: Minor x-axis

  • 3: Minor y-axis

  • 4: Major x-axis

  • 5: Major y-axis