Dear All,
I'm facing a strange problem. I did not succeed in putting some values
in an MPI matrix. I'm using Petsc 3.16.4. The matrix is pre-allocated,
with some zeroes at the right position.
To explain the context, it's a finit elements code, thus in the tangent
matrix creation, i've got a first loop over the elements, and feed the
matrix accordingly. This part is working. I'm using ADD_VALUES.
I then have to put the periodic boundary conditions on some nodes, that
is to say that i've got 1 at the diagonal, and -1 on the mirror element
of the designated ddl (i've got a Newton-Raphson minimisation
procedure). I'm using INSERT_VALUES here.
According to the documentation, i should do :
Loop over Elements
call MatSetValues
end loop
call MatAssemblyBegin(A,MAT_FLUSH_ASSEMBLY,ierr);CHKERRA(ierr)
call MatAssemblyEnd(A,MAT_FLUSH_ASSEMBLY,ierr);CHKERRA(ierr)
Loop over periodic nodes
call MatSetValue
end loop
call MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY,ierr);CHKERRA(ierr)
call MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY,ierr);CHKERRA(ierr)
But it's not working. I don't have those values from the periodic
boundary condition in the global matrix. The return value of MatSetValue
is 0.
I tried valgrind, but memory access looks ok. I really don't know how to
debug this. Do you have any idea of what could happen here ?
Debug ideas ?
Many thanks,
Best Regards,
Yann
