swh:1:snp:af87cd67498ef4fe47c76ed3e7caffe5b61facaf
Tip revision: f7ba9bfe7439ce1ebd9df172a11c6ab1b96cf388 authored by Danilo Piparo on 27 November 2023, 20:22:19 UTC
"Update ROOT version files to v6.28/10."
"Update ROOT version files to v6.28/10."
Tip revision: f7ba9bf
dirs.C
/// \file
/// \ingroup tutorial_io
/// \notebook -nodraw
/// This macro illustrates how to create a hierarchy of directories
/// in a Root file.
/// Ten directories called plane0, plane1, ..., plane9 are created.
/// Each plane directory contains 200 histograms.
/// Note that the macro deletes the TFile object at the end!
/// Connect the file again in read mode:
/// ~~~{.bash}
/// Root [0] TFile top("top.root");
/// ~~~
/// The hierarchy can be browsed by the Root browser as shown below
/// ~~~{.bash}
/// Root TBrowser b;
/// ~~~
/// Click on the left pane on one of the plane directories.
/// This shows the list of all histograms in this directory.
/// Double click on one histogram to draw it (left mouse button).
/// Select different options with the right mouse button.
/// Instead of using the browser, you can also do:
/// ~~~{.bash}
/// Root > tof->cd();
/// Root > plane3->cd();
/// Root > h3_90N->Draw();
/// ~~~
/// \macro_code
///
/// \author Rene Brun
void dirs() {
// create a new Root file
TFile *top = new TFile("top.root","recreate");
// create a subdirectory "tof" in this file
TDirectory *cdtof = top->mkdir("tof");
cdtof->cd(); // make the "tof" directory the current directory
// create a new subdirectory for each plane
const Int_t nplanes = 10;
const Int_t ncounters = 100;
char dirname[50];
char hname[20];
char htitle[80];
Int_t i,j,k;
TDirectory *cdplane[nplanes];
TH1F *hn[nplanes][ncounters];
TH1F *hs[nplanes][ncounters];
for (i=0;i<nplanes;i++) {
sprintf(dirname,"plane%d",i);
cdplane[i] = cdtof->mkdir(dirname);
cdplane[i]->cd();
// create counter histograms
for (j=0;j<ncounters;j++) {
sprintf(hname,"h%d_%dN",i,j);
sprintf(htitle,"hist for counter:%d in plane:%d North",j,i);
hn[i][j] = new TH1F(hname,htitle,100,0,100);
sprintf(hname,"h%d_%dS",i,j);
sprintf(htitle,"hist for counter:%d in plane:%d South",j,i);
hs[i][j] = new TH1F(hname,htitle,100,0,100);
}
cdtof->cd(); // change current directory to top
}
// Fill histograms
TRandom r;
for (i=0;i<nplanes;i++) {
cdplane[i]->cd();
for (j=0;j<ncounters;j++) {
for (k=0;k<100;k++) {
hn[i][j]->Fill(100*r.Rndm(),i+j);
hs[i][j]->Fill(100*r.Rndm(),i+j+k);
}
}
}
// save histogram hierarchy in the file
top->Write();
delete top;
}