[petsc-users] Loading PETSC Grid

[Alfredo J Duarte Gomez]

Good morning,

We are currently developing a PETSC application on a structured grid,
however, we are applying a curvilinear transformation so that the physical
domain is not a rectangle (the computational domain is).

As a result we are trying to load in a mesh into the PETSC dmda object to
create easy visualizations. I have successfully done this through the
following code:


ierr=VecCreateMPI(PETSC_COMM_WORLD,PETSC_DECIDE,6400,&co);CHKERRQ(ierr);
     ierr=PetscObjectSetName((PetscObject) co, "coordinates");CHKERRQ(ierr);

ierr=PetscViewerHDF5Open(PETSC_COMM_WORLD,"coord2d.h5",FILE_MODE_READ,&viewer);CHKERRQ(ierr);
     ierr=VecLoad(co,viewer);CHKERRQ(ierr);
     ierr=PetscViewerDestroy(&viewer);CHKERRQ(ierr);
     ierr=DMSetCoordinates(da,co);CHKERRQ(ierr);

Where my coordinate vector in HDF5 format is a single column vector in the
order x1,y1,x2,y2,...xN,yN,etc. where 1 is the lower left corner and N.
However this seems like a rather crude way of doing it, it seems like using
the DMGetCoordinateDM() and DMCreateGlobalVector() is a more sophisticated
way of leveraging the dmda object, however when I use:

DMGetCoordinateDM(da, &cda);
DMCreateGlobalVector(cda, &co);
ierr=PetscObjectSetName((PetscObject) co, "coordinates");CHKERRQ(ierr);
ierr=PetscViewerHDF5Open(PETSC_COMM_WORLD,"coord2d.h5",FILE_MODE_READ,&viewer);CHKERRQ(ierr);
ierr=VecLoad(co,viewer);CHKERRQ(ierr);
ierr=PetscViewerDestroy(&viewer);CHKERRQ(ierr);
ierr=DMSetCoordinates(da,co);CHKERRQ(ierr);

The loading function complains about the structure/format of my data. I
haven't been able to find the format that this coordinate dmda expects from
an HDF5 file in any of the documentation. Is there anywhere I could find
this information?

Thank you,

-Alfredo





-- 
Alfredo Duarte
Graduate Research Assistant
The University of Texas at Austin
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