How different are the values in b? Can you send back a few examples of the 
different b’s? Any idea of the condition number of C? 

   Barry

On Jun 25, 2014, at 3:10 PM, Arthur Kurlej <[email protected]> wrote:

> Hi all,
> 
> While running my code, I have found that MatMult() returns different values 
> depending on the number of processors I use (and there is quite the variance 
> in the values).
> 
> The setup of my code is as follows (I can go into more depth/background if 
> needed):
> -Generate parallel AIJ matrix of size NxN, denoted as A
> -Retrieve parallel AIJ submatrix from the last N-1 rows&columns from A, 
> denoted as C
> -Generate vector of length N-1, denoted as x
> -Find C*x=b
> 
> I have already checked that A, C, and x are all equivalent when ran for any 
> number of processors, it is only the values of vector b that varies.
> 
> Does anyone have an idea about what's going on?
> 
> 
> Thanks,
> Arthur
> 

Reply via email to