[petsc-users] questions

xiaohl xiaohl at ices.utexas.edu
Thu Nov 17 13:08:39 CST 2011


 Hi

 I got the error
 [0]PETSC ERROR: --------------------- Error Message 
 ------------------------------------
 [0]PETSC ERROR: Invalid argument!
 [0]PETSC ERROR: Not a vector next in file!

 from the line "ierr = VecLoad(u,viewer); CHKERRQ(ierr);"

 Here is my code
 Vec u;
 ierr = 
 DMDACreate3d(PETSC_COMM_WORLD,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,
 		      DMDA_BOUNDARY_NONE,DMDA_STENCIL_STAR,-4,-4,-4,
 		      PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,1,1,
 		      PETSC_NULL,PETSC_NULL,PETSC_NULL,&da); CHKERRQ(ierr);
 ierr = DMGetGlobalVector(da,&u); CHKERRQ(ierr);
 ierr = 
 PetscViewerBinaryOpen(PETSC_COMM_WORLD,"permX.bin",FILE_MODE_READ,&viewer);CHKERRQ(ierr);
 ierr = VecLoad(u,viewer); CHKERRQ(ierr);

 I just followed the example 
 "http://www.mcs.anl.gov/petsc/snapshots/petsc-dev/src/dm/examples/tutorials/ex9.c.html"
 Do you know what happened?

 Hailong


 On Wed, 2 Nov 2011 15:53:27 -0500, Barry Smith <bsmith at mcs.anl.gov> 
 wrote:
> On Nov 2, 2011, at 3:42 PM, Matthew Knepley wrote:
>
>> On Wed, Nov 2, 2011 at 8:38 PM, xiaohl <xiaohl at ices.utexas.edu> 
>> wrote:
>> Hi
>>
>> I am going to implement cell center difference method for
>> u = - K grad p
>> div u = f
>> where p is the pressure , u is the velocity, f is the source term.
>>
>> my goal is to assemble the matrix and test the performance of 
>> different linear solvers in parallel.
>>
>> my question is how can I read the input file for K where K is n*n 
>> tensor.
>>
>> MatLoad()
>
>    Hm, I think you should use a DMDA with n*n size dof and then use
> VecLoad() to load the entries of K.
>
>    Barry
>
>>
>> second one is that do you have any similar examples?
>>
>> Nothing with the mixed-discretization of the Laplacian.
>>
>>    Matt
>>
>> Hailong
>>
>>
>>
>> --
>> 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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