Libcore.so

ROOT
1

Hi ,

I am trying to run a simple test but when I use new TBrowser(); it gives me the below error. I used other I run my code using:

the code:

 #include <iostream>
#include <TRandom1.h>
#include "TFile.h"
#include "TTree.h"
#include "TFile.h"
#include "TTree.h"
#include "TBrowser.h"
#include "TH2.h"
#include "TRandom.h"
#include "TROOT.h"
using namespace std;


void tree1w()
{
   //create a Tree file tree1.root
   
   //create the file, the Tree and a few branches
   TFile f("tree1.root","recreate");
   TTree t1("t1","a simple Tree with simple variables");
   Float_t px, py, pz;
   Double_t random;
   Int_t ev;
   t1.Branch("px",&px,"px/F");
   t1.Branch("py",&py,"py/F");
   t1.Branch("pz",&pz,"pz/F");
   t1.Branch("random",&random,"random/D");
   t1.Branch("ev",&ev,"ev/I");
   
   //fill the tree
   for (Int_t i=0;i<10000;i++) {
     gRandom->Rannor(px,py);
     pz = px*px + py*py;
     random = gRandom->Rndm();
     ev = i;
     t1.Fill();
}
   t1.Write();
}
   void tree1r()
   {
      //read the Tree generated by tree1w and fill two histograms
      
      //note that we use "new" to create the TFile and TTree objects !
      //because we want to keep these objects alive when we leave this function.
      TFile *f = new TFile("tree1.root");
      TTree *t1 = (TTree*)f->Get("t1");
      Float_t px, py, pz;
      Double_t random;
      Int_t ev;
      t1->SetBranchAddress("px",&px);
      t1->SetBranchAddress("py",&py);
      t1->SetBranchAddress("pz",&pz);
      t1->SetBranchAddress("random",&random);
      t1->SetBranchAddress("ev",&ev);
      
      //create two histograms
     
      TH1F *hpx   = new TH1F("hpx","px distribution",100,-3,3);
      TH2F *hpxpy = new TH2F("hpxpy","py vs px",30,-3,3,30,-3,3);
      
      //read all entries and fill the histograms
      Long64_t nentries = t1->GetEntries();
      for (Long64_t i=0;i<nentries;i++) {
        t1->GetEntry(i);
        hpx->Fill(px);
        hpxpy->Fill(px,py);
     }
     
     //we do not close the file. We want to keep the generated histograms
     //we open a browser and the TreeViewer
     if (gROOT->IsBatch()) return;
      new TBrowser();
      cout<<"here"<<endl;
      t1->StartViewer();
     // in the browser, click on "ROOT Files", then on "tree1.root".
     //     you can click on the histogram icons in the right panel to draw them.
     // in the TreeViewer, follow the instructions in the Help button.
   
   }   

     int main() 
   {
   	TRandom1* myrand = new TRandom1();
   	for(int i=0;i<10;++i) {
   		cout << myrand->Gaus(5,1) << endl;
   	}
    tree1w();
    tree1r();
    
   	return 0;
   }

   }   [/code]

[code]gcc -o test test.cpp `root-config --cflags --glibs`
./test[/code]

and

[code]echo $LD_LIBRARY_PATH 
:/usr/local/include/root:/usr/local/include/root:/usr/local/lib/root:/usr/local/lib/root:/usr/local/cula/lib64:/usr/local/cula/lib64:/usr/local/cuda/lib64:/usr/local/cuda/lib64
 *** Break *** segmentation violation



===========================================================
There was a crash.
This is the entire stack trace of all threads:
===========================================================
#0  0x00007f5dd8ab90ee in waitpid () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007f5dd8a4be8e in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#2  0x00007f5ddd09698e in TUnixSystem::StackTrace() () from /usr/local/lib/root/libCore.so
#3  0x00007f5ddd096223 in TUnixSystem::DispatchSignals(ESignals) () from /usr/local/lib/root/libCore.so
#4  <signal handler called>
#5  0x00007f5ddcfa48e3 in TApplication::InitializeGraphics() () from /usr/local/lib/root/libCore.so
#6  0x00007f5ddcfaf391 in TBrowser::TBrowser(char const*, char const*, TBrowserImp*, char const*) () from /usr/local/lib/root/libCore.so
#7  0x0000000000401a48 in tree1r() ()
#8  0x0000000000401b62 in main ()
===========================================================


The lines below might hint at the cause of the crash.
If they do not help you then please submit a bug report at
http://root.cern.ch/bugs. Please post the ENTIRE stack trace
from above as an attachment in addition to anything else
that might help us fixing this issue.
===========================================================
#5  0x00007f5ddcfa48e3 in TApplication::InitializeGraphics() () from /usr/local/lib/root/libCore.so
#6  0x00007f5ddcfaf391 in TBrowser::TBrowser(char const*, char const*, TBrowserImp*, char const*) () from /usr/local/lib/root/libCore.so
#7  0x0000000000401a48 in tree1r() ()
#8  0x0000000000401b62 in main ()
===========================================================

Can you give me a hint?Thanks

2

Hi,

You are not compiling the code you posted, right? (or at least it is not complete…)
Could you post the complete code you are actually compiling (i.e. test.cpp)?

Cheers, Bertrand.

3

I updated the code.

4

You need a TApplication instance… Could you try to make your main() like this:

int main(int argc, char ** argv) { TApplication theApp("test_app", &argc, argv); TRandom1* myrand = new TRandom1(); for (int i=0;i<10;++i) { cout << myrand->Gaus(5,1) << endl; } tree1w(); tree1r(); theApp.Run(); return 0; }And try again?

5

Thanks alot. it is working now. But can you please tell me what this [quote] TApplication theApp(“test_app”, &argc, argv);[/quote] does here? why do you initialize it like this?

6

You’re very welcome! :slight_smile: And see for example the TApplication class documentation, and the TApplication constructor one.

Cheers, Bertrand.