void GraphDisplayerCanvas::reDesignGraph()

 {

   double min_dist=40;

   //iteration counter

   for(int l=0;l<iterations;l++)

     {

       Graph::NodeMap<double> x(mytab.mapstorage.graph);

       Graph::NodeMap<double> y(mytab.mapstorage.graph);

       XYMap<Graph::NodeMap<double> > actual_forces;

       actual_forces.setXMap(x);

       actual_forces.setYMap(y);

       lemon::dim2::Point<double> delta;

       //count actual force for each nodes

       for (NodeIt i((mytab.mapstorage).graph); i!=INVALID; ++i)

 	{

 	  //propulsation of nodes

 	  for (NodeIt j((mytab.mapstorage).graph); j!=INVALID; ++j)

 	    {

 	      if(i!=j)

 		{

 		  delta=((mytab.mapstorage).coords[i]-(mytab.mapstorage).coords[j]);

 		  double length_sqr=delta.normSquare();

 		  double length=sqrt(length_sqr);

 		  if(length_sqr<min_dist)

 		    {

 		      length_sqr=min_dist;

 		    }

 		  //normalize vector

 		  delta/=length;

 		  //calculating propulsation strength

 		  //greater distance menas smaller propulsation strength

 		  delta*=propulsation/length_sqr;

 		  actual_forces.set(i,(actual_forces[i]+delta));

 		}

 	    }

 	  //attraction of nodes, to which actual node is bound

 	  for(OutEdgeIt ei((mytab.mapstorage).graph,i);ei!=INVALID;++ei)

 	    {

 	      delta=((mytab.mapstorage).coords[i]-(mytab.mapstorage).coords[mytab.mapstorage.graph.target(ei)]);

 	      double length_sqr=delta.normSquare();

 	      double length=sqrt(length_sqr);

 	      if(length_sqr<min_dist)

 		{

 		  length_sqr=min_dist;

 		}

 	      //normalize vector

 	      delta/=length;

 	      //calculating attraction strength

 	      //greater distance means greater strength

 	      delta*=attraction*length;

 	      actual_forces.set(i,actual_forces[i]-delta);

 	    }

 	  for(InEdgeIt ei((mytab.mapstorage).graph,i);ei!=INVALID;++ei)

 	    {

 	      delta=((mytab.mapstorage).coords[i]-(mytab.mapstorage).coords[mytab.mapstorage.graph.source(ei)]);

 	      double length_sqr=delta.normSquare();

 	      double length=sqrt(length_sqr);

 	      if(length_sqr<min_dist)

 		{

 		  length_sqr=min_dist;

 		}

 	      //normalize vector

 	      delta/=length;

 	      //calculating attraction strength

 	      //greater distance means greater strength

 	      delta*=attraction*length;

 	      actual_forces.set(i,actual_forces[i]-delta);

 	    }

 	}

       for (NodeIt i((mytab.mapstorage).graph); i!=INVALID; ++i)

 	{

 	  moveNode(actual_forces[i].x, actual_forces[i].y, nodesmap[i], i);

 	}

     }

 }

 void GraphDisplayerCanvas::get_design_data(double & attraction_p, double & propulsation_p, int & iterations_p)

 {

   attraction_p=attraction;

   propulsation_p=propulsation;

   iterations_p=iterations;

 }

 void GraphDisplayerCanvas::set_attraction(double attraction_p)

 {

   attraction=attraction_p;

 }

 void GraphDisplayerCanvas::set_propulsation(double propulsation_p)

 {

   propulsation=propulsation_p;

 }

 void GraphDisplayerCanvas::set_iteration(int iterations_p)

 {

   iterations=iterations_p;

 }