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

[Tim Steinhoff]

I made a pull request.

Cheers,
Volker


2016-07-29 16:49 GMT+02:00 Barry Smith <bsmith at mcs.anl.gov>:
>
>> On Jul 28, 2016, at 2:35 AM, Tim Steinhoff <kandanovian at gmail.com> wrote:
>>
>> 2016-07-27 21:42 GMT+02:00 Barry Smith <bsmith at mcs.anl.gov>:
>>>
>>>  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.
>>
>> Thanks Barry. It would be really nice if PETSc comes with that feature
>> in future, because I would prefer not to make any changes to the PETSc
>> code that disappear with every new PETSc release.
>
>    Understood. You could make a pull request with your changes https://bitbucket.org/petsc/petsc/wiki/pull-request-instructions-git otherwise I will add it but it will take a few days since I am backlogged.
>
>    Barry
>
>>
>>>
>>>   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.
>> That would work, but we have a rather large fortran code without any
>> C. So, for now we will probably stick to your first approach and keep
>> our code fotran only.
>>
>> Thanks again,
>> Volker
>>
>>
>>>
>>>
>>>> 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
>>>
>