User-difined PC

[Dave May]

Having the first argument for PCSHELL operations being PC sounds great.
That's in keeping with the petsc pattern of the first argument being
the object being manipulated.
Then users just call PCShellGetContext() within their user defined operations.


On Tue, Sep 23, 2008 at 2:08 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:
>
> On Sep 22, 2008, at 7:59 AM, Dave May wrote:
>
>>
>>
>> Why is the first pointer in PCSHELL operations the user context
>> whereas in MATSHELL the first pointer is of type Mat ?? Seems slightly
>> inconsistent.
>>
>   Good question, these were done at different times and only later
> did we realize the inconsistency. This is something that should be fixed in
> petsc-dev.
>
>   Barry
>
> I guess the first argument for the PCSHELL should become the pc.
>
>>
>>
>> On Mon, Sep 22, 2008 at 8:31 PM, Michel Cancelliere
>> <fernandez858 at gmail.com> wrote:
>>>
>>> Hello,
>>>
>>> I have problems with the implementation of a user-defined pc, basically
>>> my
>>> program is in a cycle, for with which he is called by matlab each time it
>>> seeks to solve a linear system, the problem is that in the first
>>> iteration
>>> of the for-cycle  the preconditioner works very well, then fails to
>>> convergence. It may be some parameters that I setting wrong?
>>> I'am attaching my program code.
>>>
>>> Thank you,
>>>
>>> Michel
>>>
>>
>
>