code: def _normalize(values, num: float):
      """Scale values of ``values`` to [-0.5, 0.5]."""
      return np.asarray(values, dtype=np.float32) / (num - 1) - 0.5
  
file_path: autogluon/timeseries/src/autogluon/timeseries/utils/datetime/time_features.py
imports: from typing import Callable, List
  import numpy
  import pandas
  from .base import norm_freq_str
label_desc: Use image node_id 1 for calling a global function with example usage: _normalize(values, num) and returns: unknown