code: def hx(x):
      """measurement function - convert position to bearing"""
  
      return math.atan2(platform_pos[1], x[0] - platform_pos[0])
  
file_path: filterpy/filterpy/examples/bearing_only.py
imports: import math
  from numpy import array, asarray
  from numpy.random import randn
  import matplotlib.pyplot
  from filterpy.kalman import UnscentedKalmanFilter
  from filterpy.kalman import ScaledUnscentedKalmanFilter
  from filterpy.common import Q_discrete_white_noise
label_desc: Use image node_id 2 for calling a global function with example usage: hx(x) and returns: math