TChain

Laurent Mirabito (mirabito@in2p3.fr)
Thu, 05 Mar 1998 10:23:27 +0100


Hello,

I have the following problem using TChain
I created one TTree per run and I tried to Draw variable using TChain:

root [4] TChain ch("nt")
root [5] ch.Add("Cluster20638.root")
root [6] ch.Add("Cluster20637.root")
root [7] ch.ls()
OBJ: TChainElement nt Cluster20638.root : 0
OBJ: TChainElement nt Cluster20637.root : 0
root [8] nt->Print()
Error: No symbol nt->Print() in current scope FILE:/tmp/17867haa LINE:1
root [9] nt->Draw("Krun")
Error: No symbol nt->Draw("Krun") in current scope FILE:/tmp/17867iaa
LINE:1
But when I open file by file it works
root [0] TFile f("Cluster20638.root")
root [1] f.ls()
TFile** Cluster20638.root
TFile* Cluster20638.root
KEY: TTree nt;1 An example of a ROOT tree
root [2] nt->Print()
************************************************************************************
*Tree :nt : An example of a ROOT
tree *
*Entries : 17430 : Total Size = 662542 bytes File Size =
208130 bytes *
* : : Tree compression factor =
4.12 *
************************************************************************************
*Branch :Krun :
Krun/I *
*Entries : 17430 : Total Size = 49994 bytes File Size =
230 bytes *
*Baskets : 2 : Basket Size = 25000 bytes Compression=
217.37 *
*..................................................................................*
*Branch :Kevt :
Kevt/I *
*Entries : 17430 : Total Size = 49994 bytes File Size =
17564 bytes *
*Baskets : 2 : Basket Size = 25000 bytes Compression=
2.85 *
*..................................................................................*
*Branch :Nclus :
Nclus/i *
*Entries : 17430 : Total Size = 49996 bytes File Size =
6198 bytes *
*Baskets : 2 : Basket Size = 25000 bytes Compression=
8.07 *
*..................................................................................*
*Branch :Idet :
Idet/i *
*Entries : 17430 : Total Size = 49994 bytes File Size =
3309 bytes *
*Baskets : 2 : Basket Size = 25000 bytes Compression=
15.11 *
*..................................................................................*
*Branch :Vclu :
Vclu/F *
*Entries : 17430 : Total Size = 49994 bytes File Size =
22553 bytes *
*Baskets : 2 : Basket Size = 25000 bytes Compression=
2.22 *
*..................................................................................*
*Branch :Noiclu :
Noiclu/F *
*Entries : 17430 : Total Size = 49998 bytes File Size =
18954 bytes *
*Baskets : 2 : Basket Size = 25000 bytes Compression=
2.64 *
*..................................................................................*
*Branch :Xclu :
Xclu/F *
*Entries : 17430 : Total Size = 49994 bytes File Size =
22081 bytes *
*Baskets : 2 : Basket Size = 25000 bytes Compression=
2.26

...

Any Ideas ?
Best regards
Laurent

-- 
Laurent Mirabito 
IPN Lyon