[petsc-users] Debugging KSP output error

[TAY wee-beng]

Hi,

I run my code on 1, 2 and 3 procs. KSP is used to solve the Poisson eqn.

Using MatView and VecView, I found that my LHS matrix and RHS vec are 
the same for 1,2 and 3 procs.

However, my pressure (ans) output is the almost the same (due to 
truncation err) for 1,2 procs.

But for 3 procs, the output is the same as for the 1,2 procs for all 
values except:

1. the last few values for procs 0

2. the first and last few values for procs 1 and 2.

Shouldn't the output be the same when the LHS matrix and RHS vec are the 
same? How can I debug to find the err?


-- 
Thank you

Yours sincerely,

TAY wee-beng