code: def freq_resolution(sr, nfft):
      """
      :param: sr, sample rate
      :param: nfft, fft points
      :return: freq resolution of one point
      """
      return (sr / 2) / (nfft / 2)
  
file_path: delta/delta/data/feat/speech_feature.py
imports: import os
  import numpy
  import delta.compat
  from absl import logging
  from delta.data.feat import speech_ops
  from core.ops import py_x_ops
  from delta.data.feat import python_speech_features
label_desc: Use image node_id 11 for calling a global function with example usage: freq_resolution(sr, nfft) and returns: unknown