code: def mean_angle(
      self, smoothed: List[float], aspect_ratio: float
  ) -> Union[np.ndarray, float]:
      x_range = max(self.last_step) - min(self.last_step)
      y_extent = self.get_extent(True)
      y_range = y_extent[1] - y_extent[0]
  
      if x_range < 1e-9 or y_range < 1e-9:
          return 0
  
      angles = []
      for i in range(len(smoothed) - 1):
          dx = (self.last_step[i + 1] - self.last_step[i]) / x_range
          dy = (smoothed[i + 1] - smoothed[i]) / y_range
          angles.append(math.atan2(abs(dy) * aspect_ratio, abs(dx)))
  
      return np.mean(angles)
  
imports: import math
  from typing import Dict, List, Optional, Union
  from datetime import datetime, timedelta
  import numpy
label_desc: Use image node_id 15 for calling the Series obj's underlying member method code with example usage: obj.mean_angle(smoothed, aspect_ratio) and returns: np, int