[petsc-users] ODE Solver on multiple cores

[Barry Smith]

  Likely there is something wrong with the IFunction or RHSFunction or their Jacobians that you provide in parallel.  For the example you are running the easiest way to manage the parallelism of the data is with a DMDACreate1d(). Otherwise you need to manage the ghost point communication yourself by setting up VecScatters.

  Barry

> On Jan 13, 2016, at 1:13 PM, Hasan, Fahad <mhasan8 at vols.utk.edu> wrote:
> 
> Hello,
>  
> I have written a code to solve a simple differential equation (x’’+x’+6x=0 with initial values, x(0)=2, x’(0)=3). It works well on a single core and produces result close to theoretical answer but whenever I am trying to run the same code on multiple cores, I am getting incorrect results. It seems to me that, for multiple cores it stops after taking only 2 steps regardless of the final time and gives the final result (which is inaccurate). I tried different TSType (TSEULER, TSBEULER, TSSUNDIALS, TSCN etc.) but I always ended up with the same issue.
>  
> Can you tell me what possibly may cause this problem? Thanks in advance.
>  
> Regards,
> Fahad