code: def truerange(f):
      r"""Calculate the *True Range* value.
  
      Parameters
      ----------
      f : pandas.DataFrame
          Dataframe with columns ``high`` and ``low``.
  
      Returns
      -------
      new_column : pandas.Series (float)
          The array containing the new feature.
  
      References
      ----------
      *True High - True Low* [TS_TR]_.
  
      """
      new_column = truehigh(f) - truelow(f)
      return new_column
  
imports: from alphapy.calendrical import biz_day_month
  from alphapy.calendrical import biz_day_week
  from alphapy.globals import NULLTEXT
  from alphapy.globals import BSEP, PSEP, USEP
  from alphapy.variables import vexec
  import itertools
  import logging
  import math
  import numpy
  import pandas
label_desc: Use image node_id 47 for calling a global function with example usage: truerange(f) and returns: new_column