public virtual int[] BestSequence(ISequenceModel ts, int size)
{
int length = ts.Length();
int leftWindow = ts.LeftWindow();
int rightWindow = ts.RightWindow();
int padLength = length + leftWindow + rightWindow;
int[][] tags = new int[padLength][];
int[] tagNum = new int[padLength];
for (int pos = 0; pos < padLength; pos++)
{
tags[pos] = ts.GetPossibleValues(pos);
tagNum[pos] = tags[pos].Length;
}
var newBeam = new Beam<TagSeq>(beamSize, ScoredComparator.ASCENDING_COMPARATOR);
TagSeq initSeq = new TagSeq();
newBeam.Add(initSeq);
for (int pos = 0; pos < padLength; pos++)
{
var oldBeam = newBeam;
if (pos < leftWindow + rightWindow && exhaustiveStart)
{
newBeam = new Beam<TagSeq>(100000, ScoredComparator.ASCENDING_COMPARATOR);
}
else
{
newBeam = new Beam<TagSeq>(beamSize, ScoredComparator.ASCENDING_COMPARATOR);
}
for (IEnumerator beamI = oldBeam.GetEnumerator(); beamI.MoveNext(); )
{
Console.Out.Write(@"#");
Console.Out.Flush();
TagSeq tagSeq = (TagSeq)beamI.Current;
for (int nextTagNum = 0; nextTagNum < tagNum[pos]; nextTagNum++)
{
TagSeq nextSeq = tagSeq.Tclone();
if (pos >= leftWindow + rightWindow)
{
nextSeq.ExtendWith(tags[pos][nextTagNum], ts, size);
}
else
{
nextSeq.ExtendWith(tags[pos][nextTagNum]);
}
newBeam.Add(nextSeq);
}
}
Console.Out.WriteLine(@" done");
if (recenter)
{
double max = Double.NegativeInfinity;
for (IEnumerator beamI = newBeam.GetEnumerator(); beamI.MoveNext(); )
{
TagSeq tagSeq = (TagSeq)beamI.Current;
if (tagSeq.score > max)
{
max = tagSeq.score;
}
}
for (IEnumerator beamI = newBeam.GetEnumerator(); beamI.MoveNext(); )
{
TagSeq tagSeq = (TagSeq)beamI.Current;
tagSeq.score -= max;
}
}
}
try
{
var enumerator = newBeam.GetEnumerator();
if (enumerator.MoveNext())
{
TagSeq bestSeq = enumerator.Current;
int[] seq = bestSeq.Tags();
return seq;
}
else
return null;
}
catch (Exception e)
{
Console.Error.WriteLine(@"Beam empty -- no best sequence.");
return null;
}
}
public virtual TagSeq Tclone()
{
TagSeq o = new TagSeq();
o.info = info;
o.size = size;
o.score = score;
return o;
}
