[petsc-users] question about DA

[Likun Tan]

I made s simple test,

if i assign S[j][i]=temp[2][1][1] for all j, i; it is no problem.

while, when assign S[j][i]=temp[2][3][3] for all j, i, it gives me error.

Your last statement means that i should use temp[j][i][k] if i want to sum
over k?



On Sat, August 27, 2011 4:28 pm, Jed Brown wrote:
> On Sat, Aug 27, 2011 at 15:24, Likun Tan <likunt at andrew.cmu.edu> wrote:
>
>
>> g(temp) could be sum of temp[num][j][i] where num from 1 to N, so the
>> index k is specified.
>>
>
> It could be, but you still didn't explain how the indices i and j were
> made available to g() or what that code looks like. That is almost
> certainly your problem. You might want to try running with valgrind.
>
> Also, this is totally the wrong memory layout for performance (you want
> to sum over the last index, unfortunately this requires changing your
> interpretation of the x,y,z directions).
>