#include<vector>

TGraphErrors* DrawTGraphErrors(TString fname) {


   vector<double> x, y, xerr, yerr;
   double dumx, dumy, dumxerr, dumyerr;

   ifstream in(fname.Data());
   while (in >> dumx >> dumxerr >> dumy >> dumyerr) {
      x.push_back(dumx);
      xerr.push_back(dumxerr);
      y.push_back(dumy);
      yerr.push_back(dumyerr);
   }

   const Int_t ndata = x.size();
   Double_t *xx = new Double_t[ndata];
   Double_t *xxe = new Double_t[ndata];
   Double_t *yy = new Double_t[ndata];
   Double_t *yye = new Double_t[ndata];
   
   for (Int_t i=0; i<ndata; i++) {
      xx[i] = x[i];
      xxe[i] = xerr[i];
      yy[i] = y[i];
      yye[i] = yerr[i];
      cerr << xx[i] << " " << xxe[i] << " " << yy[i] << " " << yye[i] << endl;
   }

   TGraphErrors *g = new TGraphErrors(ndata, xx, yy, xxe, yye);
   g->SetNameTitle(fname.Data(), fname.Data());
   //g->Draw("APL");

   in.close();
   in.clear();

   return g;

}