void arrows()
{
   auto c1 = new TCanvas("c1");
   c1->Range(0, 0, 1, 1);

   auto par = new TPaveLabel(0.1, 0.8, 0.9, 0.95, "Examples of various arrows formats");
   par->SetFillColor(42);
   par->Draw();

   auto ar1 = new TArrow(0.1, 0.1, 0.1, 0.7);
   ar1->Draw();
   auto ar2 = new TArrow(0.2, 0.1, 0.2, 0.7, 0.05, "|>");
   ar2->SetAngle(40);
   ar2->SetLineWidth(2);
   ar2->Draw();
   auto ar3 = new TArrow(0.3, 0.1, 0.3, 0.7, 0.05, "<|>");
   ar3->SetAngle(40);
   ar3->SetLineWidth(2);
   ar3->Draw();
   auto ar4 = new TArrow(0.46, 0.7, 0.82, 0.42, 0.07, "|>");
   ar4->SetAngle(60);
   ar4->SetLineWidth(2);
   ar4->SetFillColor(2);
   ar4->Draw();
   auto ar5 = new TArrow(0.4, 0.25, 0.95, 0.25, 0.15, "<|>");
   ar5->SetAngle(60);
   ar5->SetLineWidth(4);
   ar5->SetLineColor(4);
   ar5->SetFillStyle(3008);
   ar5->SetFillColor(2);
   ar5->Draw();
}