/// <summary>
/// Computes O-CSTI on a similarity matrix from known relationships
/// </summary>
/// <param name="matrix">Similarities</param>
/// <param name="relationships">Relationship matrix</param>
/// <returns>Modified similarities</returns>
public static TLSimilarityMatrix Compute(TLSimilarityMatrix matrix, TLSimilarityMatrix relationships)
{
// create pseudo matrix for easy lookup
// Dictionary<sourceID, Dictionary<targetID, score>>
Dictionary <string, Dictionary <string, double> > storage = new Dictionary <string, Dictionary <string, double> >();
foreach (TLSingleLink link in matrix.AllLinks)
{
if (!storage.ContainsKey(link.SourceArtifactId))
{
storage.Add(link.SourceArtifactId, new Dictionary <string, double>());
}
storage[link.SourceArtifactId].Add(link.TargetArtifactId, link.Score);
}
// compute delta
double delta = DeltaUtils.Compute(matrix);
// iterate over every (source, target) pair
TLLinksList links = matrix.AllLinks;
links.Sort();
foreach (TLSingleLink link in links)
{
// get the set of target artifacts related to link.TargetArtifactId
// then update the value of (link.SourceArtifactId, relatedArtifact) by delta
foreach (string relatedArtifact in relationships.GetSetOfTargetArtifactIdsAboveThresholdForSourceArtifact(link.TargetArtifactId))
{
storage[link.SourceArtifactId][relatedArtifact] += storage[link.SourceArtifactId][relatedArtifact] * delta;
}
}
// build new matrix
TLLinksList newLinks = new TLLinksList();
foreach (string source in storage.Keys)
{
foreach (string target in storage[source].Keys)
{
newLinks.Add(new TLSingleLink(source, target, storage[source][target]));
}
}
newLinks.Sort();
TLSimilarityMatrix newMatrix = new TLSimilarityMatrix();
foreach (TLSingleLink link in newLinks)
{
newMatrix.AddLink(link.SourceArtifactId, link.TargetArtifactId, link.Score);
}
return(newMatrix);
}
/// <summary>
/// Computes UD-CSTI for known relationships
/// </summary>
/// <param name="sims">Similarities</param>
/// <param name="relationships">Known relationships</param>
/// <param name="feedback">User feedback</param>
/// <returns>Updated similarities</returns>
public static TLSimilarityMatrix Compute(TLSimilarityMatrix sims, TLSimilarityMatrix relationships, TLSimilarityMatrix feedback)
{
// new matrix
TLSimilarityMatrix newMatrix = new TLSimilarityMatrix();
// compute delta
double delta = DeltaUtils.Compute(sims);
// make sure the entire list is sorted
TLLinksList links = sims.AllLinks;
links.Sort();
// end condition
int correct = 0;
// iterate over each source-target pair
while (links.Count > 0 && correct < feedback.Count)
{
// get link at top of list
TLSingleLink link = links[0];
// check feedback
if (feedback.IsLinkAboveThreshold(link.SourceArtifactId, link.TargetArtifactId))
{
correct++;
// update related links
for (int i = 1; i < links.Count; i++)
{
if (link.SourceArtifactId.Equals(links[i].SourceArtifactId) &&
relationships.IsLinkAboveThreshold(link.TargetArtifactId, links[i].TargetArtifactId))
{
links[i].Score += links[i].Score * delta;
}
}
}
// remove link
newMatrix.AddLink(link.SourceArtifactId, link.TargetArtifactId, link.Score);
links.RemoveAt(0);
// reorder links
links.Sort();
}
return(newMatrix);
}
