meanptvscent(){
   gROOT->Reset();
//=========Macro generated from canvas: bb/bb
//=========  (Wed Aug 14 17:34:53 2002) by ROOT version3.02/00
   TCanvas *bb = new TCanvas("bb", "bb",179,141,700,600);

  
   bb->Range(0,0,1,1);
   bb->SetFillColor(10);
   bb->SetBorderMode(0);
   bb->SetBorderSize(2);
   gStyle->SetOptStat(0);//don't draw the statistics information
   gStyle->SetMarkerStyle(24);
   gStyle->SetMarkerColor(2);
   gStyle->SetHistLineColor(6);
   gStyle->SetAxisColor(1,"xy");
   gStyle->SetTitleColor(5);
   gStyle->SetStatColor(7);
   gStyle->SetStatTextColor(4);
   gStyle->SetFrameLineColor(1);
   gStyle->SetTitleTextColor(2);
   gStyle->SetCanvasBorderSize(0);
   gStyle->SetPadBorderSize(0);
   bb->DrawFrame(0.,0.,10.,1.);
   char charc[3];
   Int_t energe[6]={5,10,20,60,130,200};
  TString *thetitle = new TString("#bar{P}/P and #bar{#Lambda}/#Lambda vs Centrality for Au+Au at ");
  
  
  TLegend *ff=new TLegend(0.7532,0.4480,0.8737,0.8667,"","brNDC");
   for(int ik=1;ik<=6;ik++){
   TString *FileName = new TString("/direct/star+u/chengyh/centrality/analysis/result/MC_Tree/");
  
   sprintf(charc,"%d",energe[ik-1]);
   FileName->Append(charc);
   cout<<*FileName<<endl;
   FileName->Append("/ptmean.root");
   cout<<*FileName<<endl;
   TFile *bbb=new TFile(FileName->Data());
   delete FileName;

   Float_t y[9];
   Float_t ey[9];
   Float_t x[9]={1.,2.,3.,4.,5.,6.,7.,8.,9.};
   Float_t ex[9]={0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5};
   for(int ip=1;ip<=9;ip++){
     y[ip-1]=(Float_t)pbar_cent->GetBinContent(ip);
     ey[ip-1]=pbar_cent->GetBinError(ip);
     
     cout<<y[ip-1]<<" "<<ey[ip-1]<<" "<<x[ip-1]<<" "<<ex[ip-1]<<endl;   
       

 }
gr = new TGraphErrors(9,x,y,ex,ey);
gr->SetMarkerColor(1);
gr->SetMarkerColor(ik-1);
gr->SetMarkerStyle(8);
gr->Draw("p");
   
 
   for(int ip=1;ip<=9;ip++){
     y[ip-1]=(Float_t)pro_cent->GetBinContent(ip);
     ey[ip-1]=pro_cent->GetBinError(ip);
     
     cout<<y[ip-1]<<" "<<ey[ip-1]<<" "<<x[ip-1]<<" "<<ex[ip-1]<<endl;  
 

  }
   

gr = new TGraphErrors(9,x,y,ex,ey);
gr->SetMarkerColor(1);
gr->SetMarkerColor(ik-1);
gr->SetMarkerStyle(8);
gr->Draw("p");

   
 delete bbb;
   }
  bb->cd();
   bb->Modified();
   bb->cd();
   
}