code: def __init__(self, windowSize):
      super(SlopeEventWindow, self).__init__(windowSize)
      self.__x = np.asarray(range(windowSize))
  
imports: from pyalgotrade import technical
  from pyalgotrade.utils import collections
  from pyalgotrade.utils import dt
  import numpy
  from scipy import stats
label_desc: Use image node_id 1 to create a new SlopeEventWindow object from inherited base classes: technical with example: obj = SlopeEventWindow(windowSize)