--- a/c/Motion.cpp	Mon Oct 31 00:35:34 2011 -0400
+++ b/c/Motion.cpp	Mon Oct 31 19:17:42 2011 -0400
@@ -31,6 +31,8 @@
   success = trajectoryDB.read(velocities, id, velocitiesTableName);
   if (!success)
     cout << "problem loading velocities" << endl;
+  // take advantage to request first and last instant from database
+  trajectoryDB.timeInterval(firstInstant, lastInstant, id);
 }
 
 bool FeatureTrajectory::isDisplacementSmall(const unsigned int& nDisplacements, const float& minTotalFeatureDisplacement) const {
@@ -117,3 +119,4 @@
 }
 
 /******************** FeatureGraph ********************/
+

--- a/c/feature-based-tracking.cpp	Mon Oct 31 00:35:34 2011 -0400
+++ b/c/feature-based-tracking.cpp	Mon Oct 31 19:17:42 2011 -0400
@@ -273,7 +273,7 @@
   // TODO version que l'on peut interrompre ?
   for (int frameNum = params.frame1; ((frameNum-params.frame1 < params.nFrames) || (params.nFrames < 0)); frameNum++) {
     vector<int> trajectoryIds;
-    success  = trajectoryDB->trajectoryIdStartingAt(trajectoryIds, frameNum);
+    success  = trajectoryDB->trajectoryIdStartingAt(trajectoryIds, frameNum); // ending
     cout << "frame " << frameNum << " " << success << endl;
     cout << trajectoryIds.size() << " trajectories " << endl;
     BOOST_FOREACH(int trajectoryId, trajectoryIds) {
@@ -281,7 +281,8 @@
       // boost::shared_ptr<Trajectory<cv::Point2f> > trajectory;
       // success = trajectoryDB->read(trajectory, trajectoryId, "positions"); // velocities
       FeatureTrajectoryPtr ft = FeatureTrajectoryPtr(new FeatureTrajectory(trajectoryId, *trajectoryDB, "positions", "velocities"));
-      //stringstream ss;ss << *ft; cout << ss.str() << endl;
+      stringstream ss;ss << *ft; cout << ss.str() << endl;
+      cout << ft->getFirstInstant() << " " << ft->getLastInstant() << endl;
     }
 
     // should the trajectory be loaded one by one? yes

--- a/include/Motion.hpp	Mon Oct 31 00:35:34 2011 -0400
+++ b/include/Motion.hpp	Mon Oct 31 19:17:42 2011 -0400
@@ -24,13 +24,16 @@
    can be made generic for different list and blob */
   FeatureTrajectory(const int& id, TrajectoryDBAccessList<cv::Point2f>& trajectoryDB, const std::string& positionsTableName, const std::string& velocitiesTableName);
 
-  unsigned int length(void) const { return positions->size();}
+  unsigned int length(void) const { return positions->size();} // cautious if not continuous: max-min+1
 
   void setId(const unsigned int& id) { positions->setId(id);velocities->setId(id);}
 
   void setLost(void) { lost = true;}
   bool isLost(void) { return lost;}
 
+  unsigned int getFirstInstant(void) {return firstInstant;}
+  unsigned int getLastInstant(void) {return lastInstant;}
+
   /// indicates whether the sum of the last nDisplacements displacements has been inferior to minFeatureDisplacement
   bool isDisplacementSmall(const unsigned int& nDisplacements, const float& minTotalFeatureDisplacement) const;
 
@@ -50,7 +53,12 @@
   friend std::stringstream& operator<<(std::stringstream& out, const FeatureTrajectory& ft);
 
 protected:
-  bool lost;
+  bool lost; /// \todo remove
+  /// first frame number
+  unsigned int firstInstant;
+  /// last frame number
+  unsigned int lastInstant;
+
   TrajectoryPoint2fPtr positions;
   /** one fewer velocity than position
       v_n = p_n+1 - p_n*/
@@ -75,10 +83,14 @@
 // class MovingObject {}
 // roadUserType, group of features
 
-/// Class to group features
+/** Class to group features: Beymer et al. 99/Saunier and Sayed 06
+    \todo create various graph types with different parameters, that accept different feature distances or ways to connect and segment features */
 class FeatureGraph {
 public:
-  FeatureGraph(float _minDistance, float _maxDistance) : minDistance (_minDistance), maxDistance(_maxDistance) {}
+  //FeatureGraph(float _minDistance, float _maxDistance) : minDistance (_minDistance), maxDistance(_maxDistance) {}
+  FeatureGraph(float _connectionDistance, float _segmentationDistance) : connectionDistance (_connectionDistance), segmentationDistance(_segmentationDistance) {}
+
+  void addFeature(const FeatureTrajectoryPtr& ft);
 
   // add vertex, includes adding links to current vertices
   // find connected components, check if old enough, if so, remove
@@ -90,17 +102,19 @@
   };
   
   struct VertexInformation {
-    boost::shared_ptr<FeatureTrajectory> feature;
+    FeatureTrajectoryPtr feature;
   };
 
   typedef boost::adjacency_list <boost::listS, boost::listS, boost::undirectedS, VertexInformation, FeatureConnection> UndirectedGraph;
 
-  float minDistance;
-  float maxDistance;
+  float connectionDistance;
+  float segmentationDistance;
+  // float minDistance;
+  // float maxDistance;
 
   UndirectedGraph graph;
 
-  std::vector<UndirectedGraph::vertex_descriptor> currentVertices, lostVertices;
+  //std::vector<UndirectedGraph::vertex_descriptor> currentVertices, lostVertices;
 };
 
 // inlined implementations