Logo ROOT   6.14/05
Reference Guide
All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Properties Friends Macros Modules Pages
cernbuild.C File Reference

Detailed Description

View in nbviewer Open in SWAN Read data (CERN staff) from an ascii file and create a root file with a Tree.

See also a variant in staff.C

TFile *cernbuild(Int_t getFile=0, Int_t print=1) {
Int_t Category;
UInt_t Flag;
Int_t Age;
Int_t Service;
Int_t Children;
Int_t Grade;
Int_t Hrweek;
Int_t Cost;
Char_t Division[4];
Char_t Nation[3];
//The input file cern.dat is a copy of the CERN staff data base
//from 1988
TString filename = "cernstaff.root";
TString dir = gROOT->GetTutorialDir();
dir.Append("/tree/");
dir.ReplaceAll("/./","/");
FILE *fp = fopen(Form("%scernstaff.dat",dir.Data()),"r");
TFile *hfile = 0;
if (getFile) {
// if the argument getFile =1 return the file "cernstaff.root"
// if the file does not exist, it is created
if (!gSystem->AccessPathName(dir+"cernstaff.root",kFileExists)) {
hfile = TFile::Open(dir+"cernstaff.root"); //in $ROOTSYS/tutorials/tree
if (hfile) return hfile;
}
//otherwise try $PWD/cernstaff.root
if (!gSystem->AccessPathName("cernstaff.root",kFileExists)) {
hfile = TFile::Open("cernstaff.root"); //in current dir
if (hfile) return hfile;
}
}
//no cernstaff.root file found. Must generate it !
//generate cernstaff.root in $ROOTSYS/tutorials/tree if we have write access
printf("you must run the script in a directory with write access\n");
return 0;
}
hfile = TFile::Open(filename,"RECREATE");
TTree *tree = new TTree("T","CERN 1988 staff data");
tree->Branch("Category",&Category,"Category/I");
tree->Branch("Flag",&Flag,"Flag/i");
tree->Branch("Age",&Age,"Age/I");
tree->Branch("Service",&Service,"Service/I");
tree->Branch("Children",&Children,"Children/I");
tree->Branch("Grade",&Grade,"Grade/I");
tree->Branch("Step",&Step,"Step/I");
tree->Branch("Hrweek",&Hrweek,"Hrweek/I");
tree->Branch("Cost",&Cost,"Cost/I");
tree->Branch("Division",Division,"Division/C");
tree->Branch("Nation",Nation,"Nation/C");
char line[80];
while (fgets(line,80,fp)) {
sscanf(&line[0],"%d %d %d %d %d %d %d %d %d %s %s",
&Category,&Flag,&Age,&Service,&Children,&Grade,&Step,&Hrweek,&Cost,Division,Nation);
tree->Fill();
}
if (print) tree->Print();
tree->Write();
fclose(fp);
delete hfile;
if (getFile) {
//we come here when the script is executed outside $ROOTSYS/tutorials/tree
hfile = TFile::Open(filename);
return hfile;
}
return 0;
}
Author
Rene Brun

Definition in file cernbuild.C.