code: def _rangeGen(data, std=1):
      """
      Return reasonable min/max values to use given the data.
      """
      dataStd = np.std(data)
      if dataStd == 0:
          dataStd = 1
      minval = np.min(data) - std * dataStd
      maxval = np.max(data) + std * dataStd
      return minval, maxval
  
imports: import json
  import numpy
  import os
  from pkg_resources import resource_stream
label_desc: Use image node_id 2 for calling a global function with example usage: _rangeGen(data, std) and returns: minval,  maxval