# Utilities¶

## Function utilities¶

Most of the feature transformation in nnmnkwii.preprocessing module is 2d functions f: (T, D) -> (T, D'). The following utilities can be used for extending 2d functions to 3d by applying 2d function to each 2d slice.

 apply_each2d_padded(func2d, X, lengths, …) Apply function for each padded 2d slice. apply_each2d_trim(func2d, X, *args, **kwargs) Apply function for each trimmed 2d slice.

## Files¶

Part of files were taken from CMU ARCTIC dataset. Example quetsion file was taken from Merlin.

 example_label_file([phone_level]) Get path of example HTS-style full-context lable file. example_audio_file() Get path of audio file. example_question_file() Get path of example question file. example_file_data_sources_for_duration_model() Get file data sources for duration model training. example_file_data_sources_for_acoustic_model() Get file data sources for acoustic model training

## Linear algebra¶

 cholesky_inv(L[, lower]) Compute inverse matrix of real symmetric positive definite matrix using choleskey factorization. cholesky_inv_banded(L[, width])