[petsc-dev] KSP automatic reordering

[Barry Smith]

On Sep 18, 2012, at 9:07 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:

> On Tue, Sep 18, 2012 at 8:59 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
>   The problem is that users won't fix their code to use the correct ordering; they'll just have it reorder after it is made (since people are lazy), but of course this is true regardless of our interface.
> 
> Sad but true. Some people will fix it though.
>  
>       So should we strip out the diagonal scaling stuff and make it a PC?
> 
> I'm not sure. It's a true algorithmic component when using PCLSC (and was inlined in the old PCBFBT).

   Couldn't the PCLSC set up this intermediate scaling PC and "hide" it from the user?  That is the user interacts with the prefix for the final thing?


   Barry