void test()
{

ifstream in;
in.open(Form("LANSCE/data_Jan30_300k.txt"));

Float_t x,y,z,r;
Int_t nlines = 0;
std::vector<Double_t> X;
std::vector<Double_t> Y;
std::vector<Double_t> Z;


while (1) {
    in >> x >> y >> z >> r;
    X.push_back(x);
    Y.push_back(y);
    Z.push_back(z);
    if (!in.good()) break;
    nlines++;
}
in.close();

//make graph
   c0 = new TCanvas("c0","Front ",0,0,600,400);
   dt0 = new TGraph2D();
   dt0->SetTitle("LANSCE/data_Jan30_300k Back Diod");

   
//load points
   for (Int_t n=(1+nlines)/2; n<nlines+1; n++) {
cout<<n-(1+nlines)/2<<endl;
      dt0->SetPoint(n-(1+nlines)/2,X[n],Y[n],Z[n]);
   }


dt0->Draw("surf1");
dt0->GetXaxis()->SetTitle("X (cm)");
dt0->GetXaxis()->SetTitleOffset(2);

dt0->GetYaxis()->SetTitle("Y (cm)");
dt0->GetYaxis()->SetTitleOffset(2);
   
   gStyle->SetPalette(1);
   dt0->Draw("surf1");
    c0->Update();

}