[petsc-dev] Error in MatGetDiagonal_Shell?

[Smith, Barry F.]

   I don't understand

    The code has

  ierr = MatGetDiagonal(A,W2);CHKERRQ(ierr);
  ierr = VecView(W2,viewer);CHKERRQ(ierr);

   the output from this VecView seems to match the diagonal of the matrix printed earlier.

> On Apr 29, 2018, at 10:02 AM, Stefano Zampini <stefano.zampini at gmail.com> wrote:
> 
> By looking at src/mat/examples/tests/output/ex88_1.out, it seems that the output of MatGetDiagonal is wrong for MATSHELL. 
> 
> it should be 
> 2.96782e+08
> 1.41731e+09
> and not (as computed) 
> 1.10918e+08
> 2.06459e+08

   What do you mean "as computed"? The output file does not contain
> 1.10918e+08
> 2.06459e+08
anywhere.

   Are you modifying the example and running it again to get the incorrect value?

  Barry

> 
> -- 
> Stefano