--- a/c/Motion.cpp	Mon Feb 20 19:32:27 2012 -0500
+++ b/c/Motion.cpp	Fri Mar 02 19:32:54 2012 -0500
@@ -20,17 +20,17 @@
 
 /******************** FeatureTrajectory ********************/
 
-FeatureTrajectory::FeatureTrajectory(const int& frameNum, const cv::Point2f& p, const Mat& homography)
-  : lost(false) {
+FeatureTrajectory::FeatureTrajectory(const unsigned int& frameNum, const cv::Point2f& p, const Mat& homography)
+  : firstInstant(frameNum), lastInstant(frameNum) {
   positions = TrajectoryPoint2fPtr(new TrajectoryPoint2f());
   velocities = TrajectoryPoint2fPtr(new TrajectoryPoint2f());
   addPoint(frameNum, p, homography);
 }
 
-FeatureTrajectory::FeatureTrajectory(TrajectoryPoint2fPtr& _positions, TrajectoryPoint2fPtr& _velocities)
-  : lost(false) {
+FeatureTrajectory::FeatureTrajectory(TrajectoryPoint2fPtr& _positions, TrajectoryPoint2fPtr& _velocities) {
   positions = _positions;
   velocities = _velocities;
+  positions->computeInstants(firstInstant, lastInstant);
 }
 
 FeatureTrajectory::FeatureTrajectory(const int& id, TrajectoryDBAccessList<Point2f>& trajectoryDB, const string& positionsTableName, const string& velocitiesTableName) {
@@ -91,11 +91,15 @@
   return connected;
 }
 
-void FeatureTrajectory::addPoint(const int& frameNum, const Point2f& p, const Mat& homography) {
+void FeatureTrajectory::addPoint(const unsigned int& frameNum, const Point2f& p, const Mat& homography) {
   Point2f pp = p;
   if (!homography.empty())
     pp = project(p, homography);
   positions->add(frameNum, pp);
+  if (frameNum < firstInstant)
+    firstInstant = frameNum;
+  if (frameNum > lastInstant)
+    lastInstant = frameNum;
   computeMotionData(frameNum);
   assert(positions.size() == displacementDistances.size()+1);
   assert(positions.size() == velocities.size()+1);
@@ -153,14 +157,16 @@
   for (graph_traits<UndirectedGraph>::vertex_iterator vi = vertices(graph).first; 
        vi!=vertices(graph).second; ++vi) { // vi pointer to vertex_descriptor
     FeatureTrajectoryPtr ft2 = graph[*vi].feature;
-    int lastInstant = static_cast<int>(min(ft->getLastInstant(), ft2->getLastInstant()));
-    int firstInstant = static_cast<int>(max(ft->getFirstInstant(), ft2->getFirstInstant()));
-    if (lastInstant-firstInstant > static_cast<int>(minFeatureTime)) { // equivalent to lastInstant-firstInstant+1 >= minFeatureTime
-      if (ft->minMaxSimilarity(*ft2, firstInstant, lastInstant, connectionDistance, segmentationDistance)) {
-	UndirectedGraph::edge_descriptor e;
-	bool unused;
-	tie(e, unused) = add_edge(newVertex, *vi, graph);
-	// no need to add measures to graph[e] (edge properties)
+    if (newVertex != *vi) {
+      int lastInstant = static_cast<int>(min(ft->getLastInstant(), ft2->getLastInstant()));
+      int firstInstant = static_cast<int>(max(ft->getFirstInstant(), ft2->getFirstInstant()));
+      if (lastInstant-firstInstant > static_cast<int>(minFeatureTime)) { // equivalent to lastInstant-firstInstant+1 >= minFeatureTime
+	if (ft->minMaxSimilarity(*ft2, firstInstant, lastInstant, connectionDistance, segmentationDistance)) {
+	  UndirectedGraph::edge_descriptor e;
+	  bool unused;
+	  tie(e, unused) = add_edge(newVertex, *vi, graph);
+	  // no need to add measures to graph[e] (edge properties)
+	}
       }
     }
   }