%*** input graph adjacency matrix G and nodal coordinates (for visualisation):


 %    [G,XY] = getgraph;   %   creation d'un graph test
 
 %[G,XY] = getgraphTree(20);   % creation de la matrice d'adjacence "arbre"
 %[G,XY] = getgraphBus(9);   % creation de la matrice d'adjacence "bus"
 %[G,XY] = getgraphRing(9);   % creation de la matrice d'adjacence "anneau"
 [G,XY] = getgraphDoublering(9);   % creation de la matrice d'adjacence "double anneau"
 %[G,XY] = getgraphStar(9);   % creation de la matrice d'adjacence "étoile"
 %[G,XY] = getgraphDoublestar(9);   % creation de la matrice d'adjacence "double étoile"
 %[G,XY] = getgraphTrianglemesh(9);   % creation de la matrice d'adjacence "triangle mesh"
 %[G,XY] = getgraphRhomboidmesh(9);   % creation de la matrice d'adjacence "triangle mesh"
%*** nnod: number of nodes, nseg: number of segments:
  nnod = size(G,1);
  nseg = nnz(G)/2;
  
% G(5,9)=.3;G(9,5)=0.3;  %%    change le coût d'un lien

%*** same volume of data (=1) is sent from all nodes to all nodes (equipotential):
  STraffic = 0*G;
  for nfrom = 1:nnod
   for nto = 1:nnod
      if (nfrom ~= nto)
        [Paths,S] = gettraffic(G,nfrom,nto);
        STraffic = STraffic + S;
      end;
    end;
  end;
%--- STraffic(i,j) = t, (t) units of data passed through segment i-->j


%*** visualize graph and traffic:
  figure; clf
  gplot(G,XY);
  [i,j,k] = find(triu(STraffic));
  EXY = 0.3*XY(i,:) + 0.7*XY(j,:);
  tx1=text(EXY(:,1),EXY(:,2),num2str(k,'%3.1f'));
  [i,j,k] = find(triu(STraffic'));
  EXY = 0.3*XY(j,:) + 0.7*XY(i,:);
  tx2=text(EXY(:,1),EXY(:,2),num2str(k,'%3.1f'));
  hold on
  tx3 = text(XY(:,1),XY(:,2),num2str((1:nnod)'));
  set(tx1,'FontSize',18)
  set(tx2,'FontSize',18)
  set(tx3,'FontSize',18)
  set(tx3,'Color','r')
  axis equal
  axis off
  
  %**** calculate length
[lengthNet] = getlength(G,XY,nnod);
hold on, 
ti=title(strcat('length:   ',num2str(lengthNet)));
set(ti,'FontSize',16);