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.


func circle (rad, cx, cy, fill='white', stroke='black') {
    say "<circle cx='#{cx}' cy='#{cy}' r='#{rad}' fill='#{fill}' stroke='#{stroke}' stroke-width='1'/>";
}
 
func yin_yang (rad, cx, cy, fill='white', stroke='black', angle=90) {
    var (c, w) = (1, 0);
    angle != 0 && say "<g transform='rotate(#{angle}, #{cx}, #{cy})'>";
    circle(rad, cx, cy, fill, stroke);
    say("<path d='M #{cx} #{cy + rad}A #{rad/2} #{rad/2} 0 0 #{c} #{cx} #{cy} ",
        "#{rad/2} #{rad/2} 0 0 #{w} #{cx} #{cy - rad} #{rad} #{rad} 0 0 #{c} #{cx} ",
        "#{cy + rad} z' fill='#{stroke}' stroke='none' />");
    circle(rad/5, cx, cy + rad/2, fill, stroke);
    circle(rad/5, cx, cy - rad/2, stroke, fill);
    angle != 0 && say "</g>";
}
 
say '<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" version="1.1" xmlns:xlink="http://www.w3.org/1999/xlink">';
 
yin_yang(40, 50, 50);
yin_yang(20, 120, 120);
 
say '</svg>';