code: def _orientation_kernel(t):
      """structure elements for calculating the value of neighbors in several
      directions
      """
      sin = np.sin
      pi = np.pi
      t = pi * t
      arr = np.array(
          [
              [sin(t), sin(t + 0.5 * pi), sin(t + pi)],
              [sin(t + 1.5 * pi), 0, sin(t + 1.5 * pi)],
              [sin(t + pi), sin(t + 0.5 * pi), sin(t)],
          ]
      )
      return np.round(0.5 * (1 + arr) ** 2).astype(np.bool_)
  
imports: import warnings
  import numpy
  from scipy import ndimage, signal
label_desc: Use image node_id 2 for calling a global function with example usage: _orientation_kernel(t) and returns: np