private static string GetNewPathString(NBestPath path, Node newNode)
{
string newPathString;
if (newNode.Word.IsSentenceEndWord)
{
newPathString = path.Path + " </s>";
}
else if (newNode.Word.IsFiller)
{
newPathString = path.Path;
}
else
{
newPathString = path.Path + " " + newNode.Word;
}
return(newPathString);
}
public ICollection <String> GetNbest(int n)
{
Lattice.ComputeNodePosteriors(1.0f);
HashSet <String> result = new HashSet <String>();
var queue = new BoundedPriorityQueue <NBestPath>(n);
queue.Add(new NBestPath("<s>", Lattice.InitialNode, 0, 0));
while (result.Count < n && queue.Size() > 0)
{
NBestPath path = queue.Poll();
if (path.Node.Equals(Lattice.TerminalNode))
{
result.Add(path.Path);
continue;
}
foreach (Edge e in path.Node.LeavingEdges)
{
Node newNode = e.ToNode;
double newForwardScore = path.ForwardScore
+ e.AcousticScore + e.LMScore;
double newScore = newForwardScore + newNode.BackwardScore;
string newPathString = GetNewPathString(path, newNode);
NBestPath newPath = new NBestPath(newPathString, newNode, newScore, newForwardScore);
queue.Add(newPath);
}
// printQueue(queue);
}
return(result);
}
