Hi Rene,
Thanks. It works indeed but if I run two times the code to readout the
tree, Root failed and gives:
*** Break *** segmentation violation
Generating stack trace...
0x401dacbb in TUnixSystem::StackTrace(void) + 0x25b from
/usr/local/ROOT/lib/libCore.so
0x401d9812 in TUnixSystem::DispatchSignals(ESignals) + 0xb2 from
/usr/local/ROOT/lib/libCore.so
0x401d89bb in <unknown> from /usr/local/ROOT/lib/libCore.so
0x401dc585 in <unknown> from /usr/local/ROOT/lib/libCore.so
0x40e6e848 in <unknown> from /lib/i686/libc.so.6
0x40ec0bf4 in __libc_free at
/usr/src/build/40457-i686/BUILD/glibc-2.2.4/malloc/malloc.c:3155 from
/lib/i686/libc.so.6
....
I have solved the problem by opening myself a TCanvas and plotting in
it. Then it works (I don't know why) as many times as I want.
Thanks.
Pascal.
Rene Brun a écrit:
>Hi Pascal,
>
>What is the problem with your example?
>For me it works without any changes, although I suggest to modify your code
>as shown in the attachements.
>In particular, it does not make sense to use the split mode for an histogram.
>
>Rene Brun
>
>Pascal PERRODO wrote:
>
>
>>Hi rooters,
>>
>>I try to create and read Trees containing not only Int_t and Float_t,
>>but also objects (TH1F).
>>I have tried to follow the recipies in the documentation (p202, Adding a
>>TBranch to Hold an Object).
>>
>>I have written a simple example in the directory
>>/afs/cern.ch/user/p/pperrodo/public/tree/
>>tree-read.C : creates the tree tree.root and seems to work
>>tree-write.C : reads the tree and failed. Could you help me to read such
>>a tree.
>>
>>I use the Version 3.05/05 8 May 2003 on redhat.
>>
>>Many thanks in advance.
>>Regards.
>>Pascal Perrodo.
>>
>>
>>
>>
>
>------------------------------------------------------------------------
>
>// create a tree with TH1F as variable
>// P. Perrodo
>// 28/09/03
>{
>
>TH1F h0("h0","h0",100,0,100);
>
>TFile fout("tree.root","RECREATE");
>
>TTree tr1("tr1","tr1");
>
>Int_t i1;
>Float_t x1;
>TH1F *h=0; //<========
>
>tr1.Branch("i1",&i1,"i1/I");
>tr1.Branch("x1",&x1,"x1/F");
>tr1.Branch("hist", "TH1F", &h, 32000, 0); //<========
>
>for ( Int_t n=0 ; n<100 ; n++ ){
>
> i1 = n;
> x1 = n*n;
>
> h0.Reset();
> h0.Fill(n);
> h = (TH1F*) h0.Clone(); //<========
>
> tr1.Fill();
> delete h; //<========
>}
>
>tr1.Print();
>fout.Write();
>
>}
>
>
>------------------------------------------------------------------------
>
>{
>
>TFile f("tree.root");
>
>TTree *tr = (TTree*) f.Get("tr1");
>
>Int_t i1;
>Float_t x1;
>TH1F *h=0; //<========
>
>//h = new TH1F(); //<========
>
>tr->SetBranchAddress("i1",&i1);
>tr->SetBranchAddress("x1",&x1);
>TBranch *bh0 = tr->GetBranch("hist");
>bh0->SetAddress(&h);
>
>TProfile hd1("hd1","hd1",100,0,100);
>
>Int_t nentries = tr->GetEntries();
>Int_t nbytes = 0;
>for (Int_t i=0; i<nentries;i++) {
> nbytes += tr->GetEntry(i);
>
> hd1.Fill(i1,x1);
>
>}
>
>hd1.Draw();
>
>//getchar();
>
>}
>
>
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