Changelog to version 2026-09:
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> Added option to calculate derivatives of intensity time-series.

Applies to:

contour_clustering.R

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> Added options to measure formants (as time-series or singleton measure) and sample them using spectrograms. 

Applies to:

contour_clustering.R

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> Added clustering method for vowels based on centroids in acoustic space (using formant values).

Applies to:

contour_clustering.R

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> Added function to check R version.

Applies to:

contour_clustering.R

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> Improved y-axis labels when using two axes.

Applies to:

contour_clustering.R

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> Prototype calculation no longer limited to single variable

Applies to:

contour_clustering.R

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> Improved cutting audio files using tuneR package.

Applies to:

contour_clustering.R

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> Updated manual.pdf to account for the aforementioned changes.

Applies to:
- manual.pdf