[petsc-users] VecValid

[Sanjay Govindjee]

Thanks.  I think this will work for us.
-sanjay

On 5/3/12 7:22 PM, Barry Smith wrote:
>    VecValid was unsafe because it looks inside a data structure that may or not be valid.
>
>     In Fortran the safe way to do this is to set the value to 0 right after declaration and then check if not zero. So
>
>     Mat    A
>
>     A  = 0
>
>      .......
>
>      if (A .eq. 0) then
>           call VecCreate(   A,ierr)
>      endif
>
>     Barry
>
> On May 3, 2012, at 9:17 PM, Sanjay Govindjee wrote:
>
>> The entry points for our code can vary.  Thus a vector for example can get created in a handful
>> of routines.  But it is possible that the vector has already been created in another routine.  So
>> we perform a VecValid check on it.  If it is false we create it, else we go on and use it.  Also at
>> the end when we exit the program we clean up with a series of VecDestroy calls but we check first if the vector is valid before calling VecDestroy on it.  Same for MatValid/MatDestroy.
>>
>> Obviously we can store a logical flag in a common block or the like upon creation; but VecValid and
>> MatValid were handy utility functions for us.
>>
>> Is is feasible to call PetscValidHeaderSpecific( ) out of fortran?  Or should should I just set up my own
>> collection of allocate/deallocate flags.
>>
>> -sanjay
>>
>> On 5/3/12 7:08 PM, Matthew Knepley wrote:
>>> On Thu, May 3, 2012 at 9:20 PM, Sanjay Govindjee<s_g at berkeley.edu>  wrote:
>>> We have some code that has worked up through petsc-3.1 and we are in the process of updating it to petsc-3.2.
>>>
>>> One thing that I can not find mentioned in the change logs (looking all the way back to petsc-2.1.0) or the FAQs is the elimination of the VecValid and MatValid tests.
>>>
>>> In C, this is now the macro PetscValidHeaderSpecific(). This check now happens in every function call. What
>>> logic would need to look for a corrupt Vec beyond CHKERRQ?
>>>
>>>    Thanks,
>>>
>>>        Matt
>>>
>>> We used to perform operations like:
>>>
>>>       call VecValid(xvec, chk, ierr)
>>>
>>>       if(chk .eqv. PETSC_FALSE) then
>>>                 call VecCreate        (PETSC_COMM_WORLD, xvec, ierr)
>>>                 call VecSetSizes      (xvec, numpeq, PETSC_DECIDE, ierr)
>>>                 call VecSetFromOptions(xvec, ierr)
>>>       else
>>>         ....
>>>       endif
>>>
>>> But it seems VecValid and MatValid have been eliminated.  Is there a reason for this?  or have
>>> I made a mistake?  Is there a replacement test for invalid Vec and Mat pointers?
>>>
>>> -sanjay
>>>
>>>
>>>
>>>
>>> -- 
>>> What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
>>> -- Norbert Wiener
>> -- 
>> -----------------------------------------------
>> Sanjay Govindjee, PhD, PE
>> Professor of Civil Engineering
>>
>> 779 Davis Hall
>> Structural Engineering, Mechanics and Materials
>> Department of Civil Engineering
>> University of California
>> Berkeley, CA 94720-1710
>>
>> Voice:  +1 510 642 6060
>> FAX:    +1 510 643 5264
>>
>> s_g at berkeley.edu
>> http://www.ce.berkeley.edu/~sanjay
>>
>> -----------------------------------------------
>>

-- 
-----------------------------------------------
Sanjay Govindjee, PhD, PE
Professor of Civil Engineering

779 Davis Hall
Structural Engineering, Mechanics and Materials
Department of Civil Engineering
University of California
Berkeley, CA 94720-1710

Voice:  +1 510 642 6060
FAX:    +1 510 643 5264
s_g at berkeley.edu
http://www.ce.berkeley.edu/~sanjay
-----------------------------------------------