[petsc-users] how to output components of a section
leejearl
leejearl at 126.com
Wed Nov 9 23:54:04 CST 2016
Hi, Matt
Thanks for your reply, and will it be solved in the newest version
of PETSc?
leejearl
On 2016年11月07日 20:09, Matthew Knepley wrote:
> On Mon, Nov 7, 2016 at 4:17 AM, Sander Arens <Sander.Arens at ugent.be
> <mailto:Sander.Arens at ugent.be>> wrote:
>
> Ok, I see what happened.
> If you create a a vector with DMGetGlobalVector, the VecView
> function is overloaded with some DM-specific VecView function
> (e.g. VecView_Plex), but this doesn't happen with the vec that you
> get from VecGetSubVector. So one way to solve this would be to
> create a global vector from your subdm and do the scatters yourself.
> But I think it would be better if these VecView operations could
> be copied from the original vec in VecGetSubVector?
>
>
> You are right. I am moving this to petsc-dev temporarily for discussion.
>
> Thanks,
>
> Matt
>
> Thanks,
> Sander
>
> On 7 November 2016 at 09:08, leejearl <leejearl at 126.com
> <mailto:leejearl at 126.com>> wrote:
>
> Hi Sander:
> Thank your for your assistance, but it is still not works.
> The code is now as follows:
> Vec subX, X;
> DM subdm;
> IS subIS;
> PetscInt numSubFields = 2;
> PetscInt subFields[2];
> subFields[0] = 0; subFields[1] =1 ;
> ierr = DMCreateSubDM(dm, numSubFields, subFields,
> &subIS, &subdm);CHKERRQ(ierr);
> ierr = DMGetGlobalVector(dm, &X);CHKERRQ(ierr);
> ierr = VecGetSubVector(X,subIS,&subX);CHKERRQ(ierr);
> ierr = VecSetDM(subX, dm);CHKERRQ(ierr);
>
> ierr = PetscObjectSetName((PetscObject) subX,
> "sol.");CHKERRQ(ierr);
> ierr = PetscViewerSetType(*viewer,
> PETSCVIEWERVTK);CHKERRQ(ierr);
> ierr = PetscViewerPushFormat(*viewer,
> PETSC_VIEWER_VTK_VTU);CHKERRQ(ierr);
> ierr = PetscViewerFileSetName(*viewer,
> "subsol.vtu");CHKERRQ(ierr);
> ierr = VecView(subX, viewer);CHKERRQ(ierr);
> ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
> ierr = VecRestoreSubVector(X, subIS,
> &subX);CHKERRQ(ierr);
> DMDestroy(&subdm);
> ierr = DMRestoreGlobalVector(dm, &X);CHKERRQ(ierr);
>
>
>
> I have add "VecSetDm", but it has not output file.
>
> Thanks
> leejearl
>
> On 2016年11月07日 15:35, Sander Arens wrote:
>> Does it work if you put
>> ierr = VecSetDM(subX, subdm);CHKERRQ(ierr);
>> before the VecView?
>>
>> Thanks,
>> Sander
>>
>> On 7 November 2016 at 03:50, leejearl <leejearl at 126.com
>> <mailto:leejearl at 126.com>> wrote:
>>
>> Hi, Barry:
>> I must have some make some mistakes. I post the code
>> as follows:
>> Vec subX, X;
>> DM subdm;
>> IS subIS;
>> PetscInt numSubFields = 2;
>> PetscInt subFields[2];
>> subFields[0] = 0; subFields[1] =1 ;
>> ierr = DMCreateSubDM(dm, numSubFields, subFields,
>> &subIS, &subdm);CHKERRQ(ierr);
>> ierr = DMGetGlobalVector(dm, &X);CHKERRQ(ierr);
>> ierr = VecGetSubVector(X,subIS,&subX);CHKERRQ(ierr);
>> ierr = PetscObjectSetName((PetscObject) subX,
>> "sol.");CHKERRQ(ierr);
>> ierr = PetscViewerSetType(*viewer,
>> PETSCVIEWERVTK);CHKERRQ(ierr);
>> ierr = PetscViewerPushFormat(*viewer,
>> PETSC_VIEWER_VTK_VTU);CHKERRQ(ierr);
>> ierr = PetscViewerFileSetName(*viewer,
>> "subsol.vtu");CHKERRQ(ierr);
>> ierr = VecView(subX, viewer);CHKERRQ(ierr);
>> ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
>> ierr = VecRestoreSubVector(X, subIS,
>> &subX);CHKERRQ(ierr);
>> DMDestroy(&subdm);
>> ierr = DMRestoreGlobalVector(dm, &X);CHKERRQ(ierr);
>>
>> There are three fields in dm, and I want to obtain the
>> vector of the two of them. But, I can not
>> get the output file “subsol.vtu”. Can you help me with
>> the code?
>>
>> Thanks
>> leejearl
>>
>> On 2016年11月06日 12:21, Barry Smith wrote:
>>
>> On Nov 5, 2016, at 8:36 PM, leejearl
>> <leejearl at 126.com <mailto:leejearl at 126.com>> wrote:
>>
>> Hi Sander:
>> Thank you for your advices, and it works.
>> But it is only available in th local vector.
>>
>> This should work on the global vector. Please send
>> the full output of the error messages when used with
>> a global vector.
>>
>> Barry
>>
>> Is there any methods to reach this purposes in
>> the global vector?
>> Thanks
>> leejearl
>> On 2016年11月05日 19:29, Sander Arens wrote:
>>
>> You can first obtain an IS with
>> http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/DM/DMCreateSubDM.html
>> <http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/DM/DMCreateSubDM.html>
>> and with that you can obtain a subvector with
>> http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Vec/VecGetSubVector.html
>> <http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Vec/VecGetSubVector.html>
>> which you can then view the usual way.
>>
>> Thanks,
>> Sander
>>
>> On 5 November 2016 at 12:17, leejearl
>> <leejearl at 126.com <mailto:leejearl at 126.com>>
>> wrote:
>> Hi, all:
>>
>> I meet a problems which I can not
>> overcome. The programe is like the code in
>>
>> "http://www.mcs.anl.gov/petsc/petsc-current/src/dm/impls/plex/examples/tutorials/ex1.c.html
>> <http://www.mcs.anl.gov/petsc/petsc-current/src/dm/impls/plex/examples/tutorials/ex1.c.html>".
>>
>> The code create a section which has three
>> fields: u,v,w. How can I output the fields u
>> and v without together with w?
>>
>> Thanks!
>>
>>
>> leejearl
>>
>>
>>
>>
>>
>>
>>
>
>
>
>
>
> --
> 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
--
李季
西北工业大学航空学院流体力学系
Phone: 17792092487
QQ: 188524324
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