Lattice-Tool: problems with pruning

[Andreas Stolcke]

Nicola Bertoldi wrote:
> While pruning a lattice wrt posterior probs
> with this command:
>
> lattice-tool -in-lattice lattice -read-htk -out-lattice - -write-htk 
> -posterior-prune 1.0e-1
>
> I got this error
>
> Lattice::computeForwardBackward: warning: called with unreachable nodes
>
>
> If I decrease pruning threshold this error disappears.
>
> Who can help me?

If you prune too much you remove enough nodes such that some paths 
to/from the initial/final
nodes are cut off, and some nodes become unreachable.

--Andreas

>
> best regards
> Nicola
>
>