Copy a subset of a Tree to a new Tree, one branch in a separate file.
One branch of the new Tree is written to a separate file The input file has been generated by the program in $ROOTSYS/test/Event
with the command Event 1000 1 1 1
void copytree2()
{
TString dir =
"$ROOTSYS/test/Event.root";
oldfile.GetObject("T", oldtree);
for (auto activeBranchName : {"event", "fNtrack", "fNseg", "fH"}) {
}
TFile newfile(
"small.root",
"recreate");
newtree->CopyEntries(oldtree);
newtree->Print();
newfile.Write();
}
#define R__LOAD_LIBRARY(LIBRARY)
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void char Point_t Rectangle_t WindowAttributes_t Float_t Float_t Float_t Int_t Int_t UInt_t UInt_t Rectangle_t Int_t Int_t Window_t TString Int_t GCValues_t GetPrimarySelectionOwner GetDisplay GetScreen GetColormap GetNativeEvent const char const char dpyName wid window const char font_name cursor keysym reg const char only_if_exist regb h Point_t winding char text const char depth char const char Int_t count const char ColorStruct_t color const char filename
R__EXTERN TSystem * gSystem
virtual void SetFile(TFile *file=nullptr)
Set file where this branch writes/reads its buffers.
A ROOT file is composed of a header, followed by consecutive data records (TKey instances) with a wel...
virtual Bool_t ExpandPathName(TString &path)
Expand a pathname getting rid of special shell characters like ~.
virtual Bool_t AccessPathName(const char *path, EAccessMode mode=kFileExists)
Returns FALSE if one can access a file using the specified access mode.
A TTree represents a columnar dataset.
virtual TBranch * GetBranch(const char *name)
Return pointer to the branch with the given name in this tree or its friends.
virtual TTree * CloneTree(Long64_t nentries=-1, Option_t *option="")
Create a clone of this tree and copy nentries.
virtual void SetBranchStatus(const char *bname, Bool_t status=1, UInt_t *found=nullptr)
Set branch status to Process or DoNotProcess.
- Author
- Rene Brun
Definition in file copytree2.C.