/**
* /// given edges e1 and e2 from node n to nodes n1 and n2
* /// <p/>
* /// merge e1 and e2, that is, merge the scores of e1 and e2 create n' that is a merge of n1 and n2 add n' add edge e'
* /// from n to n'
* /// <p/>
* /// remove n1 and n2 and all associated edges
*
* /// @param n
* /// @param e1
* /// @param e2
*/
protected void MergeNodesAndEdgesForward(Node n, Edge e1, Edge e2)
{
Debug.Assert(Lattice.HasNode(n));
Debug.Assert(Lattice.HasEdge(e1));
Debug.Assert(Lattice.HasEdge(e2));
Debug.Assert(e1.FromNode == n);
Debug.Assert(e2.FromNode == n);
var n1 = e1.ToNode;
var n2 = e2.ToNode;
Debug.Assert(n1.HasEquivalentEnteringEdges(n1));
Debug.Assert(n1.Word.Equals(n2.Word));
// merge the scores of e1 and e2 into e1
e1.AcousticScore = MergeAcousticScores
(e1.AcousticScore, e2.AcousticScore);
e1.LMScore = MergeLanguageScores(e1.LMScore,
e2.LMScore);
// add n2's edges to n1
foreach (var e in n2.LeavingEdges)
{
e2 = n1.GetEdgeToNode(e.ToNode);
if (e2 == null)
{
Lattice.AddEdge(n1, e.ToNode,
e.AcousticScore, e.LMScore);
}
else
{
// if we got here then n1 and n2 had edges to the same node
// choose the edge with best score
e2.AcousticScore = MergeAcousticScores
(e.AcousticScore, e2.AcousticScore);
e2.LMScore = MergeLanguageScores(e.LMScore,
e2.LMScore);
}
}
// remove n2 and all associated edges
Lattice.RemoveNodeAndEdges(n2);
}
/**
* /// Internal routine used when creating a Lattice from a .LAT file
*
* /// @param lattice
* /// @param tokens
*/
public static void Load(Lattice lattice, StringTokenizer tokens)
{
string from = tokens.nextToken();
string to = tokens.nextToken();
int score = int.Parse(tokens.nextToken(), CultureInfo.InvariantCulture.NumberFormat);
Node fromNode = lattice.GetNode(from);
if (fromNode == null)
{
throw new Exception("Edge fromNode \"" + from + "\" does not exist");
}
Node toNode = lattice.GetNode(to);
if (toNode == null)
{
throw new Exception("Edge toNode \"" + to + "\" does not exist");
}
lattice.AddEdge(fromNode, toNode, score, 0.0);
}
public static Lattice ReadSlf(String fileName)
{
var lattice = new Lattice();
var @in = new LineNumberReader(new StreamReader(fileName));
String line;
var readingNodes = false;
var readingEdges = false;
var startIdx = 0;
var endIdx = 1;
var lmscale = 9.5;
while ((line = @in.ReadLine()) != null)
{
if (line.Contains("Node definitions"))
{
readingEdges = false;
readingNodes = true;
continue;
}
if (line.Contains("Link definitions"))
{
readingEdges = true;
readingNodes = false;
continue;
}
if (line.StartsWith("#"))
{
//skip commented line
continue;
}
if (readingNodes)
{
//reading node info, format:
//I=id t=start_time_sec W=word_transcription
var parts = line.Split("\\s+");
if (parts.Length != 3 || !parts[0].StartsWith("I=") || !parts[1].StartsWith("t=") || !parts[2].StartsWith("W="))
{
@in.Close();
throw new IOException("Unknown node definition: " + line);
}
var idx = Convert.ToInt32(parts[0].Substring(2), CultureInfo.InvariantCulture.NumberFormat);
//convert to milliseconds inplace
var beginTime = (long)(Convert.ToDouble(parts[1].Substring(2), CultureInfo.InvariantCulture.NumberFormat) * 1000);
var wordStr = parts[2].Substring(2);
var isFiller = false;
if (idx == startIdx || wordStr.Equals("!ENTER"))
{
wordStr = "<s>";
isFiller = true;
}
if (idx == endIdx || wordStr.Equals("!EXIT"))
{
wordStr = "</s>";
isFiller = true;
}
if (wordStr.Equals("!NULL"))
{
wordStr = "<sil>";
isFiller = true;
}
if (wordStr.StartsWith("["))
{
isFiller = true;
}
var word = new Word(wordStr, new Pronunciation[0], isFiller);
var node = lattice.AddNode(idx.ToString(CultureInfo.InvariantCulture), word, beginTime, -1);
if (wordStr.Equals("<s>"))
{
lattice.InitialNode = node;
}
if (wordStr.Equals("</s>"))
{
lattice.TerminalNode = node;
}
}
else if (readingEdges)
{
//reading edge info, format:
//J=id S=from_node E=to_node a=acoustic_score l=language_score
var parts = line.Split("\\s+");
if (parts.Length != 5 || !parts[1].StartsWith("S=") || !parts[2].StartsWith("E=") ||
!parts[3].StartsWith("a=") || !parts[4].StartsWith("l="))
{
@in.Close();
throw new IOException("Unknown edge definition: " + line);
}
var fromId = parts[1].Substring(2);
var toId = parts[2].Substring(2);
var ascore = Convert.ToDouble(parts[3].Substring(2), CultureInfo.InvariantCulture.NumberFormat);
var lscore = Convert.ToDouble(parts[4].Substring(2), CultureInfo.InvariantCulture.NumberFormat) * lmscale;
lattice.AddEdge(lattice.Nodes.Get(fromId), lattice.Nodes.Get(toId), ascore, lscore);
}
else
{
//reading header here if needed
if (line.StartsWith("start="))
{
startIdx = Convert.ToInt32(line.Replace("start=", ""), CultureInfo.InvariantCulture.NumberFormat);
}
if (line.StartsWith("end="))
{
endIdx = Convert.ToInt32(line.Replace("end=", ""), CultureInfo.InvariantCulture.NumberFormat);
}
if (line.StartsWith("lmscale="))
{
lmscale = Convert.ToDouble(line.Replace("lmscale=", ""), CultureInfo.InvariantCulture.NumberFormat);
}
}
}
foreach (var node in lattice.Nodes.Values)
{
//calculate end time of nodes depending successors begin time
foreach (var edge in node.LeavingEdges)
{
if (node.EndTime < 0 || node.EndTime > edge.ToNode.BeginTime)
{
node.EndTime = edge.ToNode.BeginTime;
}
}
}
@in.Close();
return(lattice);
}