[petsc-users] Product of matrix row times a vector

[Jeremy Theler]

On Thu, 2020-01-30 at 21:10 +0000, Smith, Barry F. wrote:

>   MatGetSubMatrix() and then do the product on the sub matrix then
> VecSum
> 

Ok, I have it working in a single-processor and throws the expected
value. Yet I have a segfault in parallel when I ask for the IS
corresponding to the rows. When I call this instruction in parallel I
get a segfault (I can post the full debug output if needed):

ISCreateStride(PETSC_COMM_WORLD, size_local, first_row, 1, &set_cols);

I tried also

ISCreateStride(PETSC_COMM_WORLD, size_global, 0, 1, &set_cols));

but it also fails with the same segfault.

What am I getting wrong?

--
jeremy