code: def ulcer_index(close, window=14, fillna=False):
      """Ulcer Index
  
      https://stockcharts.com/school/doku.php?id=chart_school:technical_indicators:ulcer_index
  
      Args:
          close(pandas.Series): dataset 'Close' column.
          window(int): n period.
          fillna(bool): if True, fill nan values.
  
      Returns:
              pandas.Series: New feature generated.
      """
      indicator = UlcerIndex(close=close, window=window, fillna=fillna)
      return indicator.ulcer_index()
  
imports: import numpy
  import pandas
  from ta.utils import IndicatorMixin
label_desc: Use image node_id 21 for calling a global function with example usage: ulcer_index(close, window, fillna) and returns: indicator