Hi, If I understand your problem, you are trying to get coincidences with some SPECT device ?? sounds weird ... And to analyse your .root file, see the examples in the 2 benchmarks (SPECT: without coincidences, and PET: with coincidences). There are 2 .C files that contains C++ code that is interpreted by the root software. See the ROOT documentation if necessary but it is disheartening as there are more than 500 pages... Just looking in the example files is sufficient. <div class="gmail_quote">2009/5/1 <<a href="mailto:e.pasca@nki.nl">e.pasca@nki.nl</a>> <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Did you compile Gate linking it with ROOT libraries? if so you should have the commands /gate/output/root </blockquote><div> ROOT is of course properly installed if he can get a root output file with some trees inside. The command related to coincidences is just unavailable when using SPECT system. Simon  </div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Edoardo ________________________________________ From: <a href="mailto:gate-users-bounces@lists.healthgrid.org">gate-users-bounces@lists.healthgrid.org</a> [<a href="mailto:gate-users-bounces@lists.healthgrid.org">gate-users-bounces@lists.healthgrid.org</a>] On Behalf Of icecreamdbb [<a href="mailto:icecreamdbb@126.com">icecreamdbb@126.com</a>] Sent: Thursday, April 30, 2009 4:57 AM To: <a href="mailto:gate-users@lists.healthgrid.org">gate-users@lists.healthgrid.org</a> Subject: [Gate-users] the problems of run the Gate macros <div><div></div><div class="h5"> Hi,Gate users ! I get three problems after I run the examples given by Gate. Take SPECT.mac for example ,the problems is 1 It never runs to the end automatically . It  always  tells  "Time set to (s) 600 G4PhysicalVolumeModel::Validate() called.  Volume of the same name and copy number ("world_P", copy 0) still exists and is being used.  WARNING: This does not necessarily guarantee it's the same  volume you originally specified in /vis/scene/add/. G4PhysicalVolumeModel::Validate() called.  Volume of the same name and copy number ("world_P", copy 0) still exists and is being used.  WARNING: This does not necessarily guarantee it's the same  volume you originally specified in /vis/scene/add/. G4PhysicalVolumeModel::Validate() called.  Volume of the same name and copy number ("world_P", copy 0) still exists and is being used.  WARNING: This does not necessarily guarantee it's the same  volume you originally specified in /vis/scene/add/. G4PhysicalVolumeModel::Validate() called.  Volume of the same name and copy number ("world_P", copy 0) still exists and is being used.  WARNING: This does not necessarily guarantee it's the same  volume you originally specified in /vis/scene/add/. G4PhysicalVolumeModel::Validate() called.  Volume of the same name and copy number ("world_P", copy 0) still exists and is being used.  WARNING: This does not necessarily guarantee it's the same  volume you originally specified in /vis/scene/add/. G4PhysicalVolumeModel::Validate() called.  Volume of the same name and copy number ("world_P", copy 0) still exists and is being used.  WARNING: This does not necessarily guarantee it's the same  volume you originally specified in /vis/scene/add/. G4PhysicalVolumeModel::Validate() called.  Volume of the same name and copy number ("world_P", copy 0) still exists and is being used.  WARNING: This does not necessarily guarantee it's the same  volume you originally specified in /vis/scene/add/. G4PhysicalVolumeModel::Validate() called.  Volume of the same name and copy number ("world_P", copy 0) still exists and is being used.  WARNING: This does not necessarily guarantee it's the same  volume you originally specified in /vis/scene/add/. G4PhysicalVolumeModel::Validate() called.  Volume of the same name and copy number ("world_P", copy 0) still exists and is being used.  WARNING: This does not necessarily guarantee it's the same  volume you originally specified in /vis/scene/add/. unexpected character after line continuation character *** G4Exception: Aborting execution *** Abort " So ,it has no output files . However , I can use another way to input the rest of  macros by myself, so it has outputs . But I wonder why it never runs to the end . 2  The userguide says "   The ROOT Object Browser when opening the GATE output file, containing : 4 histograms and 4 trees (GATE, COINCIDENCES, HITS and SINGLES) in which several variables are stored ." But mine have no coincidences . Besides that , when I enter /gate/output/root/setRootCoincidencesFlag 0 , it tells command not find . When install Gate ,I follow the installationGuide ,so I don't know the reason . 3  Who  can  tell  me the root macros which can open Gate out files .How can I see or analysis the data in file.root ?                   Waiting for your answers ! Thank you very much ! ________________________________ </div></div>网易邮箱，中国第一大电子邮件服务商<<a href="http://email.163.com" target="_blank">http://email.163.com</a>> _______________________________________________ Gate-users mailing list <a href="mailto:Gate-users@lists.healthgrid.org">Gate-users@lists.healthgrid.org</a> <a href="http://lists.healthgrid.org/mailman/listinfo/gate-users" target="_blank">http://lists.healthgrid.org/mailman/listinfo/gate-users</a> </blockquote></div>