Hi Nicolas,
Use TTree::CopyTree, not CopyAddresses
TFile f("~/nico/PH176/Analyse/fl18_cd2_coinc_#5.root");
TTree *old = (TTree*) f.Get("h900");
TFile *newfile = new TFile("newfile.root","recreate");
TTree *newTree = old->CopyTree("myselection");
newTree->Write();
Rene Brun
On Thu, 25 Apr 2002, Nicolas de Sereville wrote:
> Dear Rooters,
>
> I have a TTree with 10 branches containing experimental datas. What I want
> to do is to create another TTree with the same branches and perform a
> selection within the data.
>
> I tried to use the CopyAdresses() method, but I failed :
>
> root [0] TFile f("~/nico/PH176/Analyse/fl18_cd2_coinc_#5.root")
> root [1] TTree *old = (TTree*) f.Get("h900")
> root [2] h900->Print()
> ******************************************************************************
> *Tree :h900 : Coinc
> *
> *Entries : 16335 : Total = 730540 bytes File Size =
> 469856 *
> * : : Tree compression factor = 1.69
> *
> ******************************************************************************
> *Br 0 :strip_le :
> *
> *Entries : 16335 : Total Size= 63992 bytes File Size =
> 26187 *
> *Baskets : 8 : Basket Size= 8000 bytes Compression= 2.44
> *
> *............................................................................*
> *Br 1 :Adc_leda :
> *
> *Entries : 16335 : Total Size= 63992 bytes File Size =
> 34334 *
> *Baskets : 8 : Basket Size= 8000 bytes Compression= 1.86
> *
> *............................................................................*
> *Br 2 :strip_la :
> *
> *Entries : 16335 : Total Size= 63992 bytes File Size =
> 22936 *
> *Baskets : 8 : Basket Size= 8000 bytes Compression= 2.79
> *
> *............................................................................*
> *Br 3 :Adc_lamp :
> *
> *Entries : 16335 : Total Size= 63992 bytes File Size =
> 35032 *
> *Baskets : 8 : Basket Size= 8000 bytes Compression= 1.83
> *
> *............................................................................*
>
>
> ...... more branches ...........
>
>
>
> root [4] TTree *new = new TTree("new", "new")
> root [5] new->CopyAddresses(old)
> root [6] new->Print()
> ******************************************************************************
> *Tree :new : new
> *
> *Entries : 0 : Total = 0 bytes File Size =
> 0 *
> * : : Tree compression factor = 1.00
> *
> ******************************************************************************
>
>
> So I am not abble to see the branches for the new TTree.
> Is it a normal behavior or did I miss something??
>
> I read the 2 tutorials copytree.C but in my case I'm not interested in
> copying the whole tree or only a few branches.
>
> any hint is welcomed
>
> thanks
>
> Nicolas
>
> P.S : I'm using root 3.02/03 on RH7.2
> --
> :-------------------------------:
> : Nicolas de SEREVILLE :
> : C.S.N.S.M. :
> : Batiment 104 :
> : 91405 ORSAY Campus :
> : Tel : (+ 33) (0)1 69 15 52 29 :
> : Fax : (+ 33) (0)1 69 15 50 08 :
> :-------------------------------:
>
>
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