segfault trying to plot ntuples

From: Suvayu Ali <fatkasuvayu_at_gmail.com>
Date: Thu, 3 Jun 2010 23:52:59 -0700

Hi ROOT users,

I have been facing a very strange segfault. I have a couple of ROOT files with lots of histograms and some ntuples. I was trying to write a few methods to navigate through the root files and find the desired ntuple and plot one of the variables on to a histogram. And then scale these and overlay them on one canvas.

It works fine when I try to Draw them individually, or when I read them explicitly by using their names and Draw and overlay. But when I try to search and find them something goes wrong.

Where am I going wrong? Thanks for any help on this.

And a sample of the macro is attached. The root files I used are here: <http://hep.phys.sfu.ca/~suvayu/4roottalk/>

Backtrace: (ROOT 5.26)

---

> #8 memcpy () at ../sysdeps/x86_64/memcpy.S:526
> #9 0x00007f5cb7dcc492 in TBasket::ReadBasketBuffers (this=0x1bcb0d0, pos=576290, len=219, file=0x20f0ee0) at tree/tree/src/TBasket.cxx:367
> #10 0x00007f5cb7dd9896 in TBranch::GetBasket (this=0x1bcc500, basketnumber=0) at tree/tree/src/TBranch.cxx:1068
> #11 0x00007f5cb7dd9e05 in TBranch::GetEntry (this=0x1bcc500, entry=0, getall=0) at tree/tree/src/TBranch.cxx:1170
> #12 0x00007f5cb7667c78 in R__LoadBranch (br=0x1bcc500, entry=0, quickLoad=true) at tree/treeplayer/src/TTreeFormula.cxx:98
> #13 0x00007f5cb7679b39 in TTreeFormula::EvalInstance (this=0x1bcee20, instance=0, stringStackArg=0x0) at tree/treeplayer/src/TTreeFormula.cxx:3833
> #14 0x00007f5cb765ede2 in TSelectorDraw::ProcessFill (this=0x1c2fdd0, entry=0) at tree/treeplayer/src/TSelectorDraw.cxx:1091
> #15 0x00007f5cb769755a in TTreePlayer::Process (this=0x1c30700, selector=0x1c2fdd0, option=0x7f5cb7f1d400 "", nentries=553, firstentry=0)

>     at tree/treeplayer/src/TTreePlayer.cxx:2796


> #16 0x00007f5cb768dfb1 in TTreePlayer::DrawSelect (this=0x1c30700, varexp0=0x7f5cb73aed73 "MET>>tmp_histo(100,0,100)", selection=0x7f5cb7f1d400 "",

>     option=0x7f5cb7f1d400 "", nentries=1000000000, firstentry=0) at tree/treeplayer/src/TTreePlayer.cxx:1073


> #17 0x00007f5cb7e3a906 in TTree::Draw (this=0x1bcb720, varexp=0x7f5cb73aed73 "MET>>tmp_histo(100,0,100)", selection=0x7f5cb7f1d400 "", option=0x7f5cb7f1d400 "",

>     nentries=1000000000, firstentry=0) at tree/tree/src/TTree.cxx:3442

> #18 0x00007f5cb7e1e7fc in TTree::Draw (this=0x1bcb720, opt=0x7f5cb73aed73 "MET>>tmp_histo(100,0,100)") at include/TTree.h:259
> #19 0x00007f5cb73adce5 in plot (key=0x1b35840, canvas=0x1c374b0) at /home/jallad/codebaby/macros/sample.C:136
> #20 0x00007f5cb73adbfd in read_dir (dir=0x1b63ad0, canvas=0x1c374b0) at /home/jallad/codebaby/macros/sample.C:121
> #21 0x00007f5cb73ad59f in overlay () at /home/jallad/codebaby/macros/sample.C:51

-- 
Suvayu

Open source is the future. It sets us free.






text/x-c++src attachment: sample.C

Received on Fri Jun 04 2010 - 08:53:10 CEST