code: def _create_triangular_filter_bank(
      fft_freqs: np.ndarray, filter_freqs: np.ndarray
  ) -> np.ndarray:
      """
      Creates a triangular filter bank.
  
      Adapted from *torchaudio* and *librosa*.
  
      Args:
          fft_freqs (`np.ndarray` of shape `(num_frequency_bins,)`):
              Discrete frequencies of the FFT bins in Hz.
          filter_freqs (`np.ndarray` of shape `(num_mel_filters,)`):
              Center frequencies of the triangular filters to create, in Hz.
  
      Returns:
          `np.ndarray` of shape `(num_frequency_bins, num_mel_filters)`
      """
      filter_diff = np.diff(filter_freqs)
      slopes = np.expand_dims(filter_freqs, 0) - np.expand_dims(
          fft_freqs, 1
      )
      down_slopes = -slopes[:, :-2] / filter_diff[:-1]
      up_slopes = slopes[:, 2:] / filter_diff[1:]
      return np.maximum(np.zeros(1), np.minimum(down_slopes, up_slopes))
  
file_path: transformers/src/transformers/audio_utils.py
imports: import warnings
  from typing import Optional, Union
  import numpy
label_desc: Use image node_id 3 for calling a global function with example usage: _create_triangular_filter_bank(fft_freqs, filter_freqs) and returns: np