diff --git a/Analysis.h b/Analysis.h
index d4e8c5e8f8e0dfb6fe4826255b35959fd7334d1a..6f89efd5e8ebe68d4da8f7ca3e0bbbb44101b924 100644
--- a/Analysis.h
+++ b/Analysis.h
@@ -125,8 +125,14 @@ private:
      bool _DoesUseMethodB;  // Method B (Zhang2011a)
      bool _DoesUseMethodC;       // Method C //calculate and save results of classic in separate file
      bool _DoesUseMethodD;       // Method D--Voronoi method
+     bool _DoesUseMethodI;       // Method I--Voronoi method  modified
+                                 // no measurement are)
      std::vector<int> _StartFramesMethodD;
      std::vector<int> _StopFramesMethodD;
+
+     std::vector<int> _StartFramesMethodI;
+     std::vector<int> _StopFramesMethodI;
+
      std::vector<bool> _IndividualFDFlags;
      bool _cutByCircle;       //Adjust whether cut each original voronoi cell by a circle
      double _cutRadius;
@@ -141,6 +147,7 @@ private:
      std::vector<bool> _plotTimeseriesA;
      std::vector<bool> _plotTimeseriesC;
      std::vector<bool> _plotTimeseriesD;
+     std::vector<bool> _plotTimeseriesI;
      bool _isOneDimensional;
      bool _calcIndividualFD;  //Adjust whether analyze the individual density and velocity of each pedestrian in stationary state (ALWAYS VORONOI-BASED)
      std::string _vComponent;        // to mark whether x, y or x and y coordinate are used when calculating the velocity
@@ -156,6 +163,10 @@ private:
      std::vector<MeasurementArea_B*> _areaForMethod_B;
      std::vector<MeasurementArea_B*> _areaForMethod_C;
      std::vector<MeasurementArea_B*> _areaForMethod_D;
+     std::vector<MeasurementArea_B*> _areaForMethod_I; // we still need to know
+                                                       // the zpos of the
+                                                       // measurement are, even
+                                                       // if we don't use its polygon
 };
 
 #endif /*ANALYSIS_H_*/