code: def get_mandlebrot_escape_values(width, height):
      """Constructs the Mandlebro set for a grid of dimensions (width, height)
  
      Parameters
      ----------
      width: int
          width of the resulting grid
      height: int
          height of the resulting grid
  
      Returns
      -------
      A grid of floating point values containing the output of
      get_num_escape_turns function for each point
      """
      x_vals = np.linspace(-3, 2, width)
      y_vals = np.linspace(-1.5, 1.5, height)
  
      grid = np.meshgrid(x_vals, y_vals)
  
      v_get_num_escape_turns = np.vectorize(get_num_escape_turns)
      return v_get_num_escape_turns(*grid).astype(np.float32)
  
file_path: vispy/examples/basics/visuals/colorbar_visual.py
imports: from vispy import app
  from vispy import gloo
  from vispy.visuals.transforms import STTransform
  from vispy.visuals import ColorBarVisual, ImageVisual
  from vispy.color import Color, get_colormap
  import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: get_mandlebrot_escape_values(width, height) and returns: v_get_num_escape_turns