public void Compute(bool computeDiagonalOnly)
{
for (int i = 0; i < _SourceTokens.Count; ++i)
{
for (int j = 0; j < _TargetTokens.Count; ++j)
{
if (_Sim[i, j] != _Uncomputed)
{
continue;
}
if (computeDiagonalOnly)
{
if (i == j)
{
_Sim[i, j] = SimilarityComputers.GetTokenSimilarity(_SourceTokens[i],
_TargetTokens[j], _UseStringEditDistance, _DisabledAutoSubstitutions);
}
else
{
_Sim[i, j] = -1.0d;
}
}
else
{
_Sim[i, j] = SimilarityComputers.GetTokenSimilarity(_SourceTokens[i],
_TargetTokens[j], _UseStringEditDistance, _DisabledAutoSubstitutions);
}
}
}
}
public double this[int s, int t]
{
get
{
double result = _Sim[s, t];
if (result == _Uncomputed)
{
result = SimilarityComputers.GetTokenSimilarity(_SourceTokens[s], _TargetTokens[t],
_UseStringEditDistance, _DisabledAutoSubstitutions);
_Sim[s, t] = result;
}
return(result);
}
set
{
_Sim[s, t] = value;
}
}
private Core.EditDistance.EditDistance ComputeEditDistanceImpl_Original(
IList <Core.Tokenization.Token> sourceTokens,
IList <Core.Tokenization.Token> targetTokens,
bool computeDiagonalOnly,
Core.Tokenization.BuiltinRecognizers disabledAutoSubstitutions,
out TagAssociations alignedTags)
{
/*
* The "classic" ED approach has the problem that it doesn't detect moves
* reliably, particularly block moves. Patching up insert/delete pairs as
* moves also won't catch moves which appear as changes in the ED.
*/
if (sourceTokens == null)
{
throw new ArgumentNullException("sourceTokens");
}
if (targetTokens == null)
{
throw new ArgumentNullException("targetTokens");
}
alignedTags = null;
int i, j;
// TODO handle special cases (one/both of the arrays being empty/having no elements)
// TODO use diagonal algorithm
bool enforceFullMatrixComputation = false;
Core.EditDistance.EditDistance result =
new Core.EditDistance.EditDistance(sourceTokens.Count, targetTokens.Count, 0.0d);
// matrix which captures the similarity between two tokens as well as preassignments
SimilarityMatrix sim = new SimilarityMatrix(sourceTokens, targetTokens,
_UseStringEditDistance, disabledAutoSubstitutions);
if (enforceFullMatrixComputation)
{
// this will be fully computed by the tag aligner in most cases, but we may save a bit
// on plain text segments
sim.Compute(computeDiagonalOnly);
}
MatrixItem[,] matrix = CreateEditDistanceMatrix(sourceTokens, targetTokens);
alignedTags = TagAligner.AlignPairedTags(sourceTokens, targetTokens, sim);
if (alignedTags != null && alignedTags.Count > 0)
{
// Patch the sim matrix so that non-aligned tags can't be assigned to each other
PatchSimilarityMatrix(sim, sourceTokens, targetTokens, alignedTags);
ComputeEditDistanceMatrix_Full(matrix, sim, alignedTags);
}
else if (enforceFullMatrixComputation)
{
ComputeEditDistanceMatrix_Full(matrix, sim, alignedTags);
}
else
{
ComputeEditDistanceMatrix_Lazy(matrix, sim);
}
// readout the cheapest path
i = sourceTokens.Count;
j = targetTokens.Count;
result.Distance = matrix[i, j].Score;
while (i > 0 || j > 0)
{
EditDistanceItem item = new EditDistanceItem();
item.Resolution = EditDistanceResolution.None;
MatrixItem m = matrix[i, j];
item.Operation = m.Operation;
switch (item.Operation)
{
case EditOperation.Identity:
item.Costs = 0.0d;
--i;
--j;
break;
case EditOperation.Change:
item.Costs = _UseStringEditDistance
? (1.0d - m.Similarity)
: (1.0d - SimilarityComputers.GetTokenSimilarity(sourceTokens[i - 1], targetTokens[j - 1],
true, disabledAutoSubstitutions));
// item.Costs = (1.0d - m.Similarity);
--i;
--j;
break;
case EditOperation.Insert:
item.Costs = _InsertDeleteCosts;
--j;
break;
case EditOperation.Delete:
item.Costs = _InsertDeleteCosts;
--i;
break;
case EditOperation.Undefined:
throw new Exception("Internal ED computation error");
}
item.Source = i;
item.Target = j;
result.AddAtStart(item);
}
if (alignedTags != null && alignedTags.Count > 0)
{
// should happen before move detection
FixTagActions(sourceTokens, targetTokens, result, alignedTags);
}
// identify move operations which are pairs of insert/delete operations in the shortest path.
// Note that the comparision result is already in the matrix and we only care about identity.
// TODO we may rather use a configurable threshold than identity (1.0) to catch move operations
// of sufficiently similar items (e.g. case-insensitive)
if (_ComputeMoves)
{
int moves = DetectMoves(result, matrix);
if (moves > 0)
{
// adjust score: substract moves * (deletionCosts + insertionCosts), add moves * moveCosts
// TODO take moveDistance into account, i.e. penalty depends on distance?
result.Distance -= (double)moves * (2.0d * _InsertDeleteCosts);
result.Distance += (double)moves * _MoveCosts;
}
}
#if DEBUG
// a stream for logging. Will always be null in non-Debug builds
System.IO.TextWriter logStream = null;
bool log = false;
if (log)
{
logStream = new System.IO.StreamWriter(System.IO.Path.GetTempPath() + "/ed.log",
false, System.Text.Encoding.UTF8);
logStream.WriteLine("Source objects:");
for (int p = 0; p < sourceTokens.Count; ++p)
{
logStream.WriteLine("\t{0}:\t{1}", p, sourceTokens[p].ToString());
}
logStream.WriteLine();
logStream.WriteLine("Target objects:");
for (int p = 0; p < targetTokens.Count; ++p)
{
logStream.WriteLine("\t{0}:\t{1}", p, targetTokens[p].ToString());
}
logStream.WriteLine();
logStream.WriteLine();
if (alignedTags != null)
{
logStream.WriteLine("Tag Alignment:");
foreach (TagAssociation ta in alignedTags)
{
logStream.WriteLine("\t{0}", ta.ToString());
}
logStream.WriteLine();
logStream.WriteLine();
}
result.Dump(logStream, "Final ED");
logStream.Close();
logStream.Dispose();
logStream = null;
}
#endif
#if DEBUG
// write matrix to a temp file in HTML format
_DumpMatrix = false; // typeof(T) != typeof(char);
if (_DumpMatrix)
{
System.IO.StreamWriter wtr = new System.IO.StreamWriter(System.IO.Path.GetTempPath() + "/SimMatrix.html",
false, System.Text.Encoding.UTF8);
System.Web.UI.Html32TextWriter htmlWriter = new System.Web.UI.Html32TextWriter(wtr);
htmlWriter.WriteFullBeginTag("html");
htmlWriter.WriteFullBeginTag("body");
htmlWriter.WriteBeginTag("table");
htmlWriter.WriteAttribute("border", "1");
for (j = -1; j <= targetTokens.Count; ++j)
{
htmlWriter.WriteFullBeginTag("tr");
for (i = -1; i <= sourceTokens.Count; ++i)
{
htmlWriter.WriteFullBeginTag("td");
if (i < 0)
{
// caption row
if (j >= 0)
{
htmlWriter.Write("j={0}", j);
if (j > 0)
{
htmlWriter.WriteFullBeginTag("br");
htmlWriter.WriteFullBeginTag("b");
htmlWriter.Write(targetTokens[j - 1].ToString());
htmlWriter.WriteEndTag("b");
}
}
}
else if (j < 0)
{
// j < 0 but i >= 0 -->
htmlWriter.Write("i={0}", i);
if (i > 0)
{
htmlWriter.WriteFullBeginTag("br");
htmlWriter.WriteFullBeginTag("b");
htmlWriter.Write(sourceTokens[i - 1].ToString());
htmlWriter.WriteEndTag("b");
}
}
else
{
// content cell
htmlWriter.Write("d={0}", matrix[i, j].Score);
htmlWriter.WriteFullBeginTag("br");
htmlWriter.Write("s={0}", matrix[i, j].Similarity);
htmlWriter.WriteFullBeginTag("br");
htmlWriter.Write("o={0}", matrix[i, j].Operation.ToString());
}
htmlWriter.WriteEndTag("td");
}
htmlWriter.WriteEndTag("tr");
}
htmlWriter.WriteEndTag("table");
htmlWriter.WriteFullBeginTag("h2");
htmlWriter.Write("Result");
htmlWriter.WriteEndTag("h2");
htmlWriter.Write("Score = {0}", result.Distance);
htmlWriter.WriteFullBeginTag("ol");
for (i = 0; i < result.Items.Count; ++i)
{
htmlWriter.WriteFullBeginTag("li");
htmlWriter.Write("{0}: s={1} t={2}",
result[i].Operation.ToString(), result[i].Source, result[i].Target);
}
htmlWriter.WriteEndTag("ol");
htmlWriter.WriteEndTag("body");
htmlWriter.WriteEndTag("html");
htmlWriter.Close();
}
#endif
return(result);
}