void ErgLin() {
  gROOT->SetStyle("Plain");

  TCanvas *c1;
  c1=new TCanvas("c1","Canvas",600,600);

  const unsigned ne(11);
  double e[ne],p[ne][15],q[ne][15];

  TF1 *func=new TF1("func","sqrt([0]*[0]+[1]*[1]*x*x)",0.0,2.0);
  func->SetParameters(0.01,0.2);

  ifstream fin("ErgResn.txt");
  for(unsigned ii(0);ii<ne;ii++) {
    fin >> e[ii];
    for(int j(0);j<15;j++) {
      fin >> p[ii][j] >> q[ii][j];
    }
  }
  
  TGraphErrors *tg[5];
  
  for(int i(0);i<5;i++) {
    tg[i]=new TGraphErrors(ne);
    
    for(int j(0);j<(int)ne;j++) {
      tg[i]->SetPoint(j,e[j],p[j][3*i+1]);
      tg[i]->SetPointError(j,0,q[j][3*i+1]);
    }
    
    tg[i]->SetMarkerStyle(20);
    tg[i]->SetMarkerSize(1.5);
    if((i%2)==0) tg[i]->SetMarkerColor(2);
    if((i%2)==1) tg[i]->SetMarkerColor(3);
    tg[i]->SetLineColor(2);
    
    tg[i]->Fit("pol1");
    if((i%2)==0) tg[i]->GetFunction("pol1")->SetLineColor(2);
    if((i%2)==1) tg[i]->GetFunction("pol1")->SetLineColor(3);
    
    /*
      if(sqr) {
      tg[i]->Fit("pol1");
      if(i==0) tg[i]->GetFunction("pol1")->SetLineColor(2);
      if(i==1) tg[i]->GetFunction("pol1")->SetLineColor(3);
      } else {      tg[i]->Fit("func");
      if(i==0) tg[i]->GetFunction("func")->SetLineColor(2);
      if(i==1) tg[i]->GetFunction("func")->SetLineColor(3);
      }
    */
    
    tg[i]->SetTitle(";Photon energy (GeV);Reconstructed energy (GeV)");
    
    tg[i]->GetYaxis()->SetRangeUser(0,110);
    tg[i]->GetXaxis()->SetRangeUser(0,110);
    tg[i]->GetYaxis()->SetTitleOffset(1.2);
    
    tg[i]->Draw("AP");
    
    c1->Update();
    
    if(i==0) c1->Print("ErgLin0.png");
    if(i==1) c1->Print("ErgLin1.png");
    if(i==2) c1->Print("ErgLin2.png");
    if(i==3) c1->Print("ErgLin3.png");
    if(i==4) c1->Print("ErgLin4.png");
  }
}