delimiter, fill,
height, radius and width
options. Passing a radius will set the correct width and height, the pie
will always be a circle that fits the available space.
delimiter, fill,
height, max, min,
stroke, strokeWidth and width.
change() on it. The chart will be redrawn with
the same options that were originally passed to it.
delimiter, fill, height,
max, min, padding and
width.