code: def function(self, x, y, amp, sigma_x, sigma_y, center_x=0, center_y=0):
          
          c = amp/(2*np.pi*sigma_x*sigma_y)
          delta_x = x - center_x
          delta_y = y - center_y
          exponent = -((delta_x/sigma_x)**2+(delta_y/sigma_y)**2)/2.
          return c * np.exp(exponent)
docs: returns Gaussian