[petsc-users] Ignore command line arguments with fortran code using PETSc

[Barry Smith]

  Actually there is currently no way to PetscInitialize from Fortran without adding the command line options to the database. In the middle
of petscinitialize_() is the code fragment

  PETScParseFortranArgs_Private(&PetscGlobalArgc,&PetscGlobalArgs);
  FIXCHAR(filename,len,t1);
  *ierr = PetscOptionsInsert(NULL,&PetscGlobalArgc,&PetscGlobalArgs,t1);

  We'll need to do a bit of code refactoring to provide a Fortran petscinitializenoarguments_(). The simplest way to refactor would be to change the name of petscinitialize_ to say PetscInitializeFortran_Internal() and add a bool argument whether to process the arguments and then write two trivial routines petscinitialize_ that calls the new routine with PETSC_TRUE and petscinitializenoarguments_() that calls it with PETSC_FALSE.

   Barry

  Of course you can have a C/C++ main routine that calls PetscInitializeNoArguments(); followed by PetscInitializeFortran() and then have the bulk of your code in Fortran.


> On Jul 27, 2016, at 10:55 AM, Tim Steinhoff <kandanovian at gmail.com> wrote:
> 
> 2016-07-27 16:04 GMT+02:00 Matthew Knepley <knepley at gmail.com>:
>> On Wed, Jul 27, 2016 at 4:59 AM, Tim Steinhoff <kandanovian at gmail.com>
>> wrote:
>>> 
>>> Hi all,
>>> 
>>> we coupled PETSc with our fortran code. Is there any way to let PETSc
>>> (PetscInitialize) ignore all arguments passed by the command line?
>>> Since our code is controlled by command line arguements as well, it
>>> leads to a mess, when those arguments are read twice.
>> 
>> 
>> 1) You can use PetscInitializeNoArguments()
> 
> Thanks! I thought that function was for C/C++ only.
> 
>> 
>> 2) What goes wrong? PETSc should just ignore any options it does not
>> recognize.
> 
> 
> The problem is that our code uses the same or similar argument names
> as PETSc does and our end user should not have access to all petsc
> options.
> 
> 
>> 
>>  Thanks,
>> 
>>    Matt
>> 
>>> 
>>> Thanks and kind regards,
>>> 
>>> Volker
>> 
>> 
>> 
>> 
>> --
>> 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