13 TCanvas* graphstruct()
 
   15    TGraphStruct *gs = 
new TGraphStruct();
 
   18    TGraphNode *n0 = gs->AddNode(
"n0",
"Node 0");
 
   19    TGraphNode *n1 = gs->AddNode(
"n1",
"First node");
 
   20    TGraphNode *n2 = gs->AddNode(
"n2",
"Second node");
 
   21    TGraphNode *n3 = gs->AddNode(
"n3",
"Third node");
 
   22    TGraphNode *n4 = gs->AddNode(
"n4",
"Fourth node");
 
   23    TGraphNode *n5 = gs->AddNode(
"n5",
"5th node");
 
   24    TGraphNode *n6 = gs->AddNode(
"n6",
"Node number six");
 
   25    TGraphNode *n7 = gs->AddNode(
"n7",
"Node 7");
 
   26    TGraphNode *n8 = gs->AddNode(
"n8",
"Node 8");
 
   27    TGraphNode *n9 = gs->AddNode(
"n9",
"Node 9");
 
   29    n4->SetTextSize(0.03);
 
   30    n6->SetTextSize(0.03);
 
   31    n2->SetTextSize(0.04);
 
   35    n0->SetTextColor(kRed);
 
   37    n9->SetFillColor(kRed-10);
 
   38    n0->SetFillColor(kYellow-9);
 
   39    n7->SetFillColor(kViolet-9);
 
   42    gs->AddEdge(n0,n1)->SetLineColor(kRed);
 
   43    TGraphEdge *e06 = gs->AddEdge(n0,n6);
 
   44    e06->SetLineColor(kRed-3);
 
   60    TCanvas *c = 
new TCanvas(
"c",
"c",800,600);