text: import numpy as np
  
  def make_grid(coordinates=(-10, 10, 1)):
      """
      Returns a square grid of points determined by the input coordinates
      using nump mgrid. Used in visualization fucntions.
      """
      min_, max_, grain = coordinates
      if min_ >= max_:
          raise Exception("Min value greater than max value.")
      x_test = np.mgrid[min_:max_:grain, min_:max_:grain].reshape(2, -1).T
      if np.sqrt(x_test.shape[0]) % 2 == 0:
          size = int(np.sqrt(x_test.shape[0]))
      else:
          raise Exception('Plot topology not square!')
      return x_test, size
  