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librosa.A4_to_tuning¶
- librosa.A4_to_tuning(A4, *, bins_per_octave=12)[source]¶
Convert a reference pitch frequency (e.g.,
A4=435) to a tuning estimation, in fractions of a bin per octave.This is useful for determining the tuning deviation relative to A440 of a given frequency, assuming equal temperament. By default, 12 bins per octave are used.
This method is the inverse of
tuning_to_A4.- Parameters
- A4float or np.ndarray [shape=(n,), dtype=float]
Reference frequency(s) corresponding to A4.
- bins_per_octaveint > 0
Number of bins per octave.
- Returns
- tuningfloat or np.ndarray [shape=(n,), dtype=float]
Tuning deviation from A440 in (fractional) bins per octave.
See also
Examples
The base case of this method in which A440 yields 0 tuning offset from itself.
>>> librosa.A4_to_tuning(440.0) 0.
Convert a non-A440 frequency to a tuning offset relative to A440 using the default of 12 bins per octave.
>>> librosa.A4_to_tuning(432.0) -0.318
Convert two reference pitch frequencies to corresponding tuning estimations at once, but using 24 bins per octave.
>>> librosa.A4_to_tuning([440.0, 444.0], bins_per_octave=24) array([ 0., 0.313 ])