Re: Parallel_Simulation

["John B. Matthews" <nospam@nospam.invalid>]

In article <kgfdsp$tb0$1@ccpntc8.in2p3.fr>,
 Vincent LAFAGE <lafage@ipno.in2p3.fr> wrote:

> I am interested in MonteCarlo simulation and I had translated a 
> former F77 code to Ada with success, with the goal of parallelizing 
> it, but one part in the algorithm still resists parallelization: the 
> random number generator. I need the different worker to rely on 
> independant random number generators.
> 
> Then I found a precious example in
>  RM-A-5-2 59., 60., 61.
> that compiles smoothly.
> 
> I will now attempt to check the independance of the sequence 
> generated by each thread. But this kind of check is always more 
> subtle than expected.
> 
> I wonder whether there is a statement about the independance of such 
> generator, in particular in the gnat implementation?

You should check your implementation's required documentation and any 
statements on implementation advice. For example, GNAT includes a 
comment in Ada.Numerics.Float_Random.ads, and the GNAT Reference Manual 
says, "The generator period is sufficiently long for the first condition 
here [A.5.2(47)] to hold true."

-- 
John B. Matthews
trashgod at gmail dot com
<http://sites.google.com/site/drjohnbmatthews>