> Is ok. But to have the label rotated I did
>
> \pnode(0.94366,2.10268){U}
> \pnode(5.78241,3.8267){V}
> \ncline[linewidth=0.2pt]{<->}{U}{V}
> \ncput*{\quad}
> \rput[c]{27}(3.40,2.99){$h_{_b}$}
>
> But this is not elegant (it is awful).
>
> How to proceed in such cases?
uput