This works !!
I did as you said, i.e I create my *file, THEN I create my *tree, and
just before writing this tree, I come back to the directory of the file
with file.cd(). This (basic!!) step was missing ! Indeed, between
creating the tree and writing it, I did open (then close) an other file,
so there was a problem.
Thank you very much for all.
Matthieu.
On Mon, 29 Sep 2003, Rene Brun wrote:
> I can only repeat my original request. Send the piece of code where
> you create/open/close ALL your Root files, fill the Tree, etc.
> I remind you that filling a Tree may imply writing to a file!
> In general a tree does not fit in memory.
>
> Rene Brun
>
> Matthieu Lechowski wrote:
> >
> > On Mon, 29 Sep 2003, Rene Brun wrote:
> >
> > > You should not do:
> > >
> > > TTree *TREE = new TTree(...)
> > > TFile *myfile=new TFile(name_ntuple, "RECREATE");
> > > ...
> > > TREE->Write();
> > >
> > > but
> > >
> > > TFile *myfile=new TFile(name_ntuple, "RECREATE");
> > > TTree *TREE = new TTree(...)
> > > ...
> >
> > Yes but here I open a file of data, fill my Tree, and close the file,
> > and after that TREE->Write(); doesn't work.
> >
> > > TREE->Write();
> > >
> > > Rene Brun
> > >
> > > Matthieu Lechowski wrote:
> > > >
> > > > Hello,
> > > >
> > > > It's not easy to have a simplified version of my code, but if it's
> > > > necessary I will provide you.
> > > >
> > > > I understand why the 2nd solution did not work: actually, I have to
> > > > open a second file where I get data to fill my Tree.
> > > >
> > > > So I have this order of instructions:
> > > >
> > > > TTree *TREE = new TTree(...)
> > > > TFile *data_file = new TFile(name_data_file);
> > > > //..fill tree
> > > > data_file->Close();
> > > >
> > > > TFile *myfile=new TFile(name_ntuple, "RECREATE");
> > > > TREE->Write();
> > > > myfile->Close(); //"delete myfile;" doesn't work
> > > >
> > > > I just have changed the place of data_file->Close(). Indeed it was at
> > > > the end, so when I tried to put "TFile *myfile=new ..." at the top as you
> > > > said, of course the TREE->Write() wanted write in "data_file" instead of
> > > > "myfile" (that's why I had the message "... not writable", I did not see
> > > > that the message concerned "data_file" and not "myfile", sorry).
> > > >
> > > > But even placing data_file->Close() before writing the tree, it does not
> > > > work when I put "TFile *myfile=new ..." at the top.
> > > >
> > > > ----
> > > > In conclusion, I have to manage 2 files, and I want write a Tree in one
> > > > of them. The instructions above work for small files, but not for big
> > > > ones.
> > > > Do you see where could be the problem ?
> > > >
> > > > Matthieu.
> > > >
> > > > On Mon, 29 Sep 2003, Rene Brun wrote:
> > > >
> > > > > I am afraid that we will not make any progress without looking at a simplified
> > > > > version of your code reproducing this problem.
> > > > >
> > > > > Rene Brun
> > > > >
> > > > > Matthieu Lechowski wrote:
> > > > > >
> > > > > > Hello,
> > > > > > Thanks, but unfortunately it doesn't work.
> > > > > > The first solution doesn't change anything, and with the second ROOT
> > > > > > tells me my file is not writable (Error in <TTree::Write>: File ... is
> > > > > > not writable).
> > > > > > Have you others ideas ?
> > > > > > Thank you.
> > > > > >
> > > > > > Matthieu.
> > > > > >
> > > > > > On Fri, 26 Sep 2003, Rene Brun wrote:
> > > > > >
> > > > > > > Matthieu,
> > > > > > >
> > > > > > > This seems to be a problem with the destructor of your TTree when
> > > > > > > you close the file.
> > > > > > > You can try two solutions:
> > > > > > > 1- after TREE.Write(); add the statement
> > > > > > > TREE.SetFile(0);
> > > > > > >
> > > > > > > 2- Do not create your Tree in the stack, but in the heap with
> > > > > > > TFile *myfile=new TFile(name_ntuple, "RECREATE");
> > > > > > > TTree *TREE = new TTRee(...
> > > > > > > //..fill tree
> > > > > > > TREE->Write();
> > > > > > > delete myfile; //do not delete TREE
> > > > > > >
> > > > > > > Rene Brun
> > > > > > >
> > > > > > > Matthieu Lechowski wrote:
> > > > > > > >
> > > > > > > > Hello,
> > > > > > > >
> > > > > > > > ROOT leaves without saying anything when I try to write a TTree in a
> > > > > > > > TFile, and the file has only few bytes (and can not be opened of
> > > > > > > > course).
> > > > > > > >
> > > > > > > > I have a global tree: TTree TREE("T","TREE");
> > > > > > > > In a function, I fill it, then:
> > > > > > > > TFile *myfile=new TFile(name_ntuple, "RECREATE");
> > > > > > > > TREE.Write();
> > > > > > > > myfile->Close();
> > > > > > > >
> > > > > > > > This is the way I always used, and it always worked, but this time I
> > > > > > > > have a big Tree and this doesn't work, I don't know why.
> > > > > > > > Its size is less than the limit 2Gb, I think it should be around 80Mb
> > > > > > > > with 100.000 entries (I have already a similar file of 8Mb with 10.000
> > > > > > > > entries that I succeeded to write).
> > > > > > > >
> > > > > > > > Have you an idea of what goes wrong ?
> > > > > > > > Thank you.
> > > > > > > >
> > > > > > > > Matthieu Lechowski
> > > > > > > > LAL Orsay
> > > > > > > >
> > > > > > > > lxplus
> > > > > > > > ROOTSYS=/afs/cern.ch/sw/root/v3.05.05/rh73_gcc2952/root
> > > > > > >
> > > > >
> > >
>
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