code: def psi(i, j, k, offset=(50, 50, 100)):
      x = i - offset[0]
      y = j - offset[1]
      z = k - offset[2]
      th = np.arctan2(z, np.hypot(x, y))
      r = np.sqrt(x**2 + y**2 + z**2)
      a0 = 2
      return (
          (1.0 / 81.0)
          * 1.0
          / (6.0 * np.pi) ** 0.5
          * (1.0 / a0) ** (3 / 2)
          * (r / a0) ** 2
          * np.exp(-r / (3 * a0))
          * (3 * np.cos(th) ** 2 - 1)
      )
  
imports: import numpy
  import pyqtgraph
  import pyqtgraph.opengl
  from pyqtgraph import functions
label_desc: Use image node_id 1 for calling a global function with example usage: psi(i, j, k, offset) and returns: unknown