code: def disk(x, y, height, gaussian_width):
      
      disk_radius = height/2.0
  
      distance_from_origin = np.sqrt(x**2+y**2)
      distance_outside_disk = distance_from_origin - disk_radius
      sigmasq = gaussian_width*gaussian_width
  
      if sigmasq==0.0:
          falloff = x*0.0
      else:
          with float_error_ignore():
              falloff = np.exp(np.divide(-distance_outside_disk*distance_outside_disk,
                                    2*sigmasq))
  
      return np.where(distance_outside_disk<=0,1.0,falloff)
docs: Circular disk with Gaussian fall-off after the solid central region.