> In Matlab, a stemseries object has 2 children:
> - a line object for all stems: the key here is that the original x/y
> data are
> converted into [x0 x0 NaN x1 x1 NaN...] [B y0 NaN B y1 NaN...] where B is
> the base value; line segments containing NaN are not drawn by Matlab
> - a line object for the markers
>
> The base line is a (extended) line object that is a child of the axes and
> shared by all stemseries objects within the same plot.
Oh, that's interesting. So the stem series is just a single line in some sense
with a bunch of blank spots along the way.