{
  TCanvas *c1 = new TCanvas("c1", "c1", 700, 500);
  c1->SetLogy();
  c1->SetGridx();
  c1->SetGridy();
  TF1 *logn = new TF1("logn", "TMath::LogNormal(x, [0], [1], [2])", 0, 5);
  logn->SetMinimum(1e-3);
  logn->SetParameters(0.5, 0., 1.);
  logn->SetLineColor(2);
  TF1 *logn1 = logn->DrawCopy("L");
  logn->SetParameters(1.0, 0., 1.);
  logn->SetLineColor(3);
  TF1 *logn2 = logn->DrawCopy("LSAME");
  logn->SetParameters(2.0, 0., 1.);
  logn->SetLineColor(4);
  TF1 *logn3 = logn->DrawCopy("LSAME");
  logn->SetParameters(5.0, 0., 1.);
  logn->SetLineColor(6);
  TF1 *logn4 = logn->DrawCopy("LSAME");
  auto legend = new TLegend(0.15, 0.15, 0.5, 0.35);
  legend->AddEntry(logn1, "sigma = 0.5, theta = 0, m = 1", "L");
  legend->AddEntry(logn2, "sigma = 1.0, theta = 0, m = 1", "L");
  legend->AddEntry(logn3, "sigma = 2.0, theta = 0, m = 1", "L");
  legend->AddEntry(logn4, "sigma = 5.0, theta = 0, m = 1", "L");
  legend->Draw();
}