I've accomplished this feature via: ax = axis() set(gca().
> hlines([0.], ax, ax), linewidth=1)
> I don't remember why I did it this way instead of just
> plotting. Maybe I thought is was more clever. Does this
> method avoid auto-scaling? -g
Yes it does, only because hlines doesn't call autoscale (I just looked
it up). This is probably a bug, since I don't see why the plot and
hlines method should have different behavior. It looks like an
I think plotting the horizontal extent in axes coords is the proper
way to go.