RobustPath : Unsupported types for -: 'tuple' and 'tuple'

[tristanmelton]

Hey,

I am trying to define a ring with modulation on the width. I'm using a RobustPath with a parametric to define the ring geometry and width functions (see below). when I try and get the bounding box for the path, I get the error that "Unsupported types for -: 'tuple' and 'tuple'. Is there some problem with my code? Seems like a potential bug with RobustPath.

           rb = gdspy.RobustPath([(ring_width + ring_radius + dev_dx, -(wg_width/2 + gap + ring_width/2 + ring_radius) + dev_dy)], width=ring_width, tolerance=path_tol, layer=layer_WGS, max_points=maximum_points)
            #rb.turn(ring_radius, math.radians(360), ring_width)
            #rb.turn(ring_radius, math.radians(0), math.radians(36), ring_width)
            #rb.arc(ring_radius, math.radians(0), math.radians(360))
            rb.parametric(curve_function=lambda u: (-ring_radius + ring_radius*math.cos(2*math.pi*u), ring_radius*math.sin(2*math.pi*u)), width=[lambda u: numpy.cos(2*numpy.pi*u)])
            #ring = gdspy.Round((ring_width + ring_radius + dev_dx, -(wg_width/2 + gap + ring_width/2 + ring_radius) + dev_dy), ring_radius+ring_width/2,ring_radius - ring_width/2, tolerance=path_tol, layer=layer_WGS)
           self.cell.add(rb)


            ## SSC ##
           self.cell.add(gdspy.CellReference(cell_ssc,(0, dev_dy), rotation=180))
           self.cell.add(gdspy.CellReference(cell_ssc,(chip_width_dev, dev_dy + dy)))

          
            # Create offsets for group                       
           dev_dx = dev_dx + ring_width + 2*ring_radius + ring_width + wg_width + 2*wg_sep
           dev_dy = dev_dy + wg_sep

           if ii == 0:
                dy_prime = dy

           self.top = dev_dy - wg_sep
           self.bottom = -dy_prime
           bbox = self.cell.get_bounding_box()

[heitzmann]

Please take a look at the documentation: your parametric function must return numpy arrays.