[Gate-users] Parallel simulations without cluster-aware version of Gate

[Sébastien Laberge]

Hi,

I am trying to split my Gate jobs into many processes to speed up my  
simulations. I have access to a computer cluster but not to a  
cluster-aware version of Gate. To get things going nonetheless, I  
decided not to use the jobsplitter and to use on the cluster a build  
of the regular version of Gate 7.0 available on the website. I am now  
wondering whether my approach is correct.

Right now, I am manually dividing my simulation macro file into  
several versions, which differ only by the name of the output file and  
the initial and final time of simulation, as set using the macro  
functions /gate/application/setTimeStart and  
/gate/application/setTimeStop. I set these times so that the whole  
acquisition time is divided into regular intervals, one for each  
process.

I am only simulating models of tumors (in voxelized volumes) that fit  
into the scanner's field of view. I neither need to modify the  
geometry during the simulation nor to divide the simulation into more  
than one run.

To keep the simulations realistic, my only worry is that the activity  
in the voxelized volume be adjusted at the beginning of each process  
to take into account the attenuation of activity due to radioactive  
decay during the time interval separating the initial time of the  
entire acquisition and the beginning of the time interval being  
simulated in a given process.

I guess my question could be divided into three parts :

1-When using setTimeStart to set the initial time to something other  
than zero, is the activity in the voxelized volume adjusted  
automatically by Gate to take into account activity attenuation or  
should I do that manually on the input of each process I call?

2-Apart maybe from simulation time optimization, does there seem to be  
anything I am overlooking that would render my approach fundamentally  
flawed?

3-In case I have to resort to using a cluster-aware version of Gate,  
how can I have access to it?

Thank you