void Example() {

TFile *fp = new TFile("parameters_ru98RIV0309_R1.root","RECREATE");
TTree *TREE = new TTree("TREE","data from ru98RIV0309_R1");
TREE->ReadFile("parameters_ru98RIV0309_R1.txt","PeakArea:PeakError");
TREE->Scan();
TREE->Show(0);
Double_t P1A1 = TREE->GetLeaf("PeakArea")->GetValue(0);
Double_t P1eA1 = TREE->GetLeaf("PeakError")->GetValue(0);
printf("P1A1 = %d   P1eA1= %d\n", P1A1, P1eA1);
TREE->Show(1);
TREE->GetEvent(1);
Double_t P2A1 = TREE->GetLeaf("PeakArea")->GetValue(1);
Double_t P2eA1 = TREE->GetLeaf("PeakError")->GetValue(1);
printf("P2A1 = %d   P2eA1= %d\n", P2A1, P2eA1);
TREE->Show(2);
Double_t P3A1 = TREE->GetLeaf("PeakArea")->GetValue(2);
Double_t P3eA1 = TREE->GetLeaf("PeakError")->GetValue(2);
printf("P3A1 = %d   P3eA1= %d\n", P3A1, P3eA1);

}