Params and saving svg

[mationai]

Maybe I'm missing something but it seems like Params don't play well with math. For eg., I was trying to making the 4 constants in my code below Params, but it complains that TypeError: unsupported operand type(s) for +: 'Param' and 'complex'.

    def draw(self, vsk: vsketch.Vsketch) -> None:
        vsk.size('a0', landscape=False, center=False)
        vsk.scale('mm')

        width = 700
        height = 1100
        sm_mark_len = 2.5
        bg_mark_len = 5

        vsk.line(0,0, width, 0)
        vsk.line(0,0, 0, height)
        for x in range(1, width // 10 +1):
            if x % 10 != 0:
                vsk.line(x*10,0, x*10,sm_mark_len)
            else:
                vsk.line(x*10,0, x*10,bg_mark_len)
        for y in range(1, height // 10 +1):
            if y % 10 != 0:
                vsk.line(0,y*10, sm_mark_len,y*10)
            else:
                vsk.line(0,y*10, bg_mark_len,y*10)

Also, seems like there's no UI to save/export the svg. If there's no plan to add that to the UI, is there a better way to save the svg besides vsk.save('out.svg') in the code?