[petsc-users] A number of questions about DMDA with SNES and Quasi-Newton methods

[Smith, Barry F.]

> On Nov 3, 2017, at 10:59 AM, zakaryah . <zakaryah at gmail.com> wrote:
> 
> Hi - I think I managed to get this to work.  The second call to FormCoupleLocations is actually pretty simple - it just has to set the matrix values!  One thing that was hard to figure out was why line 168 calls  MatGetOwnershipRange(*J,&__rstart,NULL) instead of also getting the last row owned.  Anyway, I did that from within FormCoupleLocations and it seems to work great!  I can try to clean things up to contribute an example if it would be useful.

   That would be great! We'd really appreciate it. As is clear from the examples we don't do a good job explaining and helping people with this concept and your example would really help everyone who needs to do this kind of thing.

   Barry

>  I'd probably either replace the finite strain with infinitesimal, or go to 1D, because in my code the Jacobian function is absurdly long and that could be distracting from the main point to exemplify, which is setting up and preallocating the fully coupled redundant field.