[petsc-users] How to view petsc array?

[TAY wee-beng]

On 21/7/2015 7:28 PM, Matthew Knepley wrote:
> On Tue, Jul 21, 2015 at 1:35 AM, TAY wee-beng <zonexo at gmail.com 
> <mailto:zonexo at gmail.com>> wrote:
>
>     Hi,
>
>     I need to check the contents of the array which was declared using:
>
>     PetscScalar,pointer ::
>     u_array(:,:,:),v_array(:,:,:),w_array(:,:,:),p_array(:,:,:)
>
>     I tried to use :
>
>     call PetscViewerASCIIOpen(MPI_COMM_WORLD,"pres.txt",viewer,ierr)
>
>     call VecView(p_array,viewer,ierr)
>
>     or
>
>     call MatView(p_array,viewer,ierr)
>
>     call PetscViewerDestroy(viewer,ierr)
>
>     but I got segmentation error. So is there a PETSc routine I can use?
>
>
> No. Those routines work only for Vec objects. You could
>
>  a) Declare a DMDA of the same size
>
>  b) Use DMDAVecGetArrayF90() to get out the multidimensional array
>
>  c) Use that in your code
>
>  d) Use VecView() on the original vector

Hi,

Supposed I need to check the contents of the u_array which was declared 
using:

PetscScalar,pointer :: u_array(:,:,:)

call 
DMDACreate3d(MPI_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_STAR,size_x,size_y,&

size_z,1,PETSC_DECIDE,PETSC_DECIDE,1,stencil_width,lx,PETSC_NULL_INTEGER,PETSC_NULL_INTEGER,da_u,ierr)

call DMDAVecGetArrayF90(da_u,u_local,u_array,ierr)

call PetscViewerASCIIOpen(MPI_COMM_WORLD,"u.txt",viewer,ierr)

call VecView(array,viewer,ierr)

call PetscViewerDestroy(viewer,ierr)

Is this the correct way?
>
>    Matt
>
>
>     -- 
>     Thank you
>
>     Yours sincerely,
>
>     TAY wee-beng
>
>
>
>
> -- 
> 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

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