Re: [ROOT] Crash on Drawing

From: Bertalan Juhasz (Bertalan.Juhasz@cern.ch)
Date: Thu Aug 15 2002 - 22:12:45 MEST


Hi Rene and Federico,

I see a very similar (probably the same) problem on RH6.1/egcs-1.1.2. I
wrote a _standalone_ program which reads data from a TNtuple, fills a
TGraphErrors, draws it (so far everything works) but when I fit it with a
TF1 (a very simple one, a single exponential), it crashes right after the
fitting (fit results are printed correctly) and the fitted function never
appears on the canvas. gdb says:

Program received signal SIGSEGV, Segmentation fault.
0x408407c6 in TGraph::PaintFit ()
   from /home/juhaszbe/install/root/new/lib/libGraf.so
(gdb) bt
#0  0x408407c6 in TGraph::PaintFit ()
   from /home/juhaszbe/install/root/new/lib/libGraf.so
#1  0x40841646 in TGraph::PaintGraph ()
   from /home/juhaszbe/install/root/new/lib/libGraf.so
#2  0x40840125 in TGraph::Paint ()
   from /home/juhaszbe/install/root/new/lib/libGraf.so
#3  0x4084c170 in TGraphErrors::Paint ()
   from /home/juhaszbe/install/root/new/lib/libGraf.so
#4  0x40a338cc in TPad::PaintModified ()
   from /home/juhaszbe/install/root/new/lib/libGpad.so
#5  0x40a33876 in TPad::PaintModified ()
   from /home/juhaszbe/install/root/new/lib/libGpad.so
#6  0x40a1c007 in TCanvas::Update ()
   from /home/juhaszbe/install/root/new/lib/libGpad.so
#7  0x804a5a4 in ?? ()
#8  0x411201eb in __libc_start_main (main=0x80496d8, argc=4,
argv=0xbffffaf4, 
    init=0x804935c, fini=0x804b384, rtld_fini=0x4000a610 <_dl_fini>, 
    stack_end=0xbffffaec) at ../sysdeps/generic/libc-start.c:90

The .so files (version 3.03/07) are directly from the ROOT website. Same
crash happens if I try to fit using the FitPanel.

Regards,

Bertalan



On Wed, 14 Aug 2002, Rene Brun wrote:

> Hi Federico,
> 
> I cannot reproduce your problem on my system (RH6.1,gcc295.2).
> I have no access to a RH7.2/gcc2.96 before tomorrow.
> Here is what I get when running your script
> 911 lines counted
> Device Name: bwsh51995.rot
> Scan Direction: OUT
> 905 data points found
> Peak= 1886
> XLOW 10426.3 XHIGH 12159.7
> par0=11137.4 par1=781.138
>  **********
>  **    1 **SET ERR           1
>  **********
> drawing
> drawn
> 
>  RESULTS:
>  RMS Data        = 781.137545
>  FWHM            = 866.724589
>  Sigma Fit1      = 781.131624
>  Sigma Fit2      = 781.137545
> file written
> done
> 
> and the corresponding c.gif file in attachement.
> Let me know if both output look reasonable.
> Note that in your code, you define twice ifstream finput!
> 
> Could somebody running RH7.2 with either gcc2.95, 2.96 or 3.0,1
> run this test to see if you also get a crash.
> Could you run under gdb and tell me the traceback when the program
> crashes?
> 
> Rene Brun
> 
> On Wed, 14 Aug 2002, Federico Roncarolo wrote:
> 
> > Hello,
> > 
> > I'm using version 3.03/07 on linux/redhat 7.2.
> > 
> > I'm loading my code with .L and then calling main(argument).
> > 
> > I'm getting data from an ascii file, filling graphs and fitting the
> > graphs.
> > Later when I just draw the graph I expect to see the graph with the
> > fitting function, but root crashes, it displays an empty canvas and gives
> > a
> > 
> >  *** Break *** segmentation violation.
> > 
> > 
> > I fit with a user-defined function with the options "QRME+".
> > If I add the options "NO", when drawing the graph everything works, but of
> > course I get only the graph and not the function.
> > 
> > The segmentation violation comes at the end of code and not just after
> > drawing.
> > 
> > Please find attached the file.C and the data file I give as argument of
> > the main function.
> > The line where I fit is number 252.
> > 
> > I changed from RH7.1 to RH7.2 ten days ago and re-installed ROOT from the
> > file 
> > 
> > root_v3.03.07.Linux.RH7.2.gcc296.tar.gz
> > 
> > I test few small codes and they look to work... any idea about what is
> > wrong?
> > 
> > Thanks a lot,
> > Federico
> > 
> 



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