Hi, I have simulated NCAT Phantom with CylindricalPET system for 1 s and obtain the root file. I try to convert root to sinogram based on Dr Rose Schmidtlein and Dr Sadek program. However there is segmentation violation error. I tried with root file generated in hoffman brain voxelised phantom example in Gate and there is no error. I would like to know what might cause this. Is the root file corrupted or something. I hope anyone who experience this can share their views. Thank you ##################################################################################### siti@siti-desktop:~/Root2Sinogram$ ./a.out /home/siti/Root2Sinogram/NCATRoot NCATSinogram Input file name is /home/siti/Root2Sinogram/NCATRoot*.root Michelogram file name is = Mich_NCATSinogram.s Projection file name is = Proj_NCATSinogram.s Warning in <TClass::TClass>: no dictionary for class TH1D is available Warning in <TClass::TClass>: no dictionary for class TH1 is available Warning in <TClass::TClass>: no dictionary for class TAxis is available Total Number of Coincidence Events:= 9275 *** Break *** segmentation violation =========================================================== There was a crash (#7 0xb71b620b in SigHandler(ESignals) () from /home/siti/Gate/root/lib/libCore.so). This is the entire stack trace of all threads: =========================================================== #0 0xb7719424 in __kernel_vsyscall () #1 0xb6b82943 in waitpid () from /lib/i386-linux-gnu/libc.so.6 #2 0xb6b09ff3 in ?? () from /lib/i386-linux-gnu/libc.so.6 #3 0xb6c83e2b in system () from /lib/i386-linux-gnu/libpthread.so.0 #4 0xb71ae57b in TUnixSystem::Exec(char const*) () from /home/siti/Gate/root/lib/libCore.so #5 0xb71b3554 in TUnixSystem::StackTrace() () from /home/siti/Gate/root/lib/libCore.so #6 0xb71b60f7 in TUnixSystem::DispatchSignals(ESignals) () from /home/siti/Gate/root/lib/libCore.so #7 0xb71b620b in SigHandler(ESignals) () from /home/siti/Gate/root/lib/libCore.so #8 0xb71aced2 in sighandler(int) () from /home/siti/Gate/root/lib/libCore.so #9 <signal handler called> #10 0x0804ad32 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 <a href="http://root.cern.ch/bugs">http://root.cern.ch/bugs</a>. Please post the ENTIRE stack trace from above as an attachment in addition to anything else that might help us fixing this issue. =========================================================== #10 0x0804ad32 in main () ===========================================================