One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.



Task

   Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
   Generate and display the symbol for two different (small) sizes.


 
with(plottools):
with(plots):
yingyang := r -> display(
                         circle([0, 0], r), 
                         disk([0, 1/2*r], 1/10*r, colour = black), 
                         disk([0, -1/2*r], 1/10*r, colour = white), 
                         disk([0, -1/2*r], 1/2*r, colour = black), 
                         inequal({1/4*r^2 <= x^2 + (y - 1/2*r)^2, 1/4*r^2 <= x^2 + (y + 1/2*r)^2, x^2 + y^2 <= 
                                  r^2}, x = 0 .. r, y = -r .. r, grid = [100, 100], colour = black), 
                         scaling = constrained, axes = none
                         );
 