|Message: Re: Cylindrical Parameterisation Causes Poor Performance||Not Logged In (login)|
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Hi Joseph, parameterisations over phi can definitely be problematic for performance as they imply recalculation of trigonometric parameters every time the shape gets changed... no surprise! If you're application is performance critical, I suggest you to use simple placements instead for such specific constructs. Cheers, Gabriele ---------------- On Tue, 19 Jul 2016 21:53:42 GMT, Joseph DeCunha wrote: > Hi there! > > I've just finished coding a cylindrical parameterisation (derived from > G4VPVParameterisation) class that parameterises along the radius and rho > axis. > > I'm implementing it in a parallel world in order to score dose. However, > I've found that compared to other G4VPVParameterisation classes I've > used the performance overhead is tremendous. For 200 particles my > simulation time hopped from 4s to 45s. > > I've narrowed the performance hit down to two statements in my > ComputeDimensions method. My cylinder.SetDeltaPhiAngle and > cylinder.SetStartPhiAngle statements. When I comment these two > statements out my performance again returns to an acceptable level. > > The number of parameterisations that I create does have some impact on > performance -- but I've tried everything from 2500 to 30 > parameterisations and the performance is still very poor. > > I was wondering if this was a known phenomenon or if anyone could help > push me in the right direction towards what may be behind the problem. > > All the best, and thanks in advance > > Joseph