--- a/c/Motion.cpp	Tue Sep 27 00:34:03 2011 -0400
+++ b/c/Motion.cpp	Tue Sep 27 01:38:05 2011 -0400
@@ -9,7 +9,10 @@
 using namespace std;
 using namespace cv;
 
-FeatureTrajectory::FeatureTrajectory(const int& frameNum, const cv::Point2f& p, const Mat& homography) {
+/******************** FeatureTrajectory ********************/
+
+FeatureTrajectory::FeatureTrajectory(const int& frameNum, const cv::Point2f& p, const Mat& homography)
+  : lost(false) {
   addPoint(frameNum, p, homography);
 }
 
@@ -95,3 +98,5 @@
     displacementDistances.push_back(dist);
   }
 }
+
+/******************** FeatureGraph ********************/

--- a/c/feature-based-tracking.cpp	Tue Sep 27 00:34:03 2011 -0400
+++ b/c/feature-based-tracking.cpp	Tue Sep 27 01:38:05 2011 -0400
@@ -141,6 +141,8 @@
 
   vector<FeatureTrajectoryPtr> lostFeatures;
   vector<FeaturePointMatch> featurePointMatches;
+
+  FeatureGraph graph(params.mmConnectionDistance, params.mmSegmentationDistance);
     
   int key = '?';
   unsigned int savedFeatureId=0;

--- a/include/Motion.hpp	Tue Sep 27 00:34:03 2011 -0400
+++ b/include/Motion.hpp	Tue Sep 27 01:38:05 2011 -0400
@@ -4,6 +4,7 @@
 #include "src/Trajectory.h"
 
 #include <boost/shared_ptr.hpp>
+#include <boost/graph/adjacency_list.hpp>
 
 template<typename T> class TrajectoryDBAccess;
 
@@ -18,6 +19,9 @@
 
   void setId(const unsigned int& id) { positions.setId(id);velocities.setId(id);}
 
+  void setLost(void) { lost = true;}
+  bool isLost(void) { return lost;}
+
   /// indicates whether the sum of the last nDisplacements displacements has been inferior to minFeatureDisplacement
   bool smallDisplacement(const unsigned int& nDisplacements, const float& minTotalFeatureDisplacement) const;
 
@@ -35,6 +39,7 @@
 #endif
 
 protected:
+  bool lost;
   Trajectory<cv::Point2f> positions;
   /** one fewer velocity than position
       v_n = p_n+1 - p_n*/
@@ -52,4 +57,32 @@
 // class MovingObject {}
 // roadUserType, group of features
 
+/// Class to group features
+class FeatureGraph {
+public:
+  FeatureGraph(float _minDistance, float _maxDistance) : minDistance (_minDistance), maxDistance(_maxDistance) {}
+
+protected:
+  struct FeatureConnection {
+    float minDistance;
+    float maxDistance;
+  };
+  
+  struct VertexInformation {
+    boost::shared_ptr<FeatureTrajectory> feature;
+  };
+
+  typedef boost::adjacency_list <boost::listS, boost::listS, boost::undirectedS, VertexInformation, FeatureConnection> UndirectedGraph;
+
+  float minDistance;
+  float maxDistance;
+
+  UndirectedGraph graph;
+
+  std::vector<UndirectedGraph::vertex_descriptor> currentVertices, lostVertices;
+};
+
+// inlined implementations
+// inline FeatureGraph::FeatureGraph(float _minDistance, float _maxDistance)
+
 #endif