code: def format_coord(x, y):
      col = round(x)
      row = round(y)
      nrows, ncols = X.shape
      if 0 <= col < ncols and 0 <= row < nrows:
          z = X[row, col]
          return f"x={x:1.4f}, y={y:1.4f}, z={z:1.4f}"
      else:
          return f"x={x:1.4f}, y={y:1.4f}"
  
label_desc: Use image node_id 1 for calling a global function with example usage: format_coord(x, y) and returns: str, x, str, y, str, z, str, x, str, y